This piece to me is the easiest slot to fill. Maybe I'm just not discriminating, but almost any calendar application works fine for me. As long as I can add appointments with all the standard stuff (reminders, time zones, etc.), I'm pretty happy. The biggest headache with calendars is keeping them in sync. Back in the bad old days of Lotus Notes at ThoughtWorks, I basically ignored the corporate calendar, keeping all my stuff in Google Calendar instead and giving people who cared an HTML view into my work calendar. Google calendar is quite nice, including good synchronization / replication with iCal. Most of my interaction with Google calendar was through the web interface, so much that I created a fluid application that had only my calendar. One of the slick tricks you can do with fluid applications is make all the chrome disappear, giving me a full-screen calendar bound to one of my desktops that looked like the wallpaper for that desktop, which was nice because you get the biggest possible calendar. I also liked the 4 views afforded by Google calendar: 1 day, 1 week, 1 month, and next 4 days.
Since ThoughtWorks moved our infrastructure to Google applications, I just exported my old work calendar and sucked it into the new ThoughtWorks Google calendar. My itineraries, my wife's schedule, etc. I subscribe to (and share subscriptions to interesting events with her). We each "own" our own calendar and cross-subscribe to get shared events. Using sites like TripIt makes keeping travel under control and subscribable. Going forward, I want all calendar stuff delivered as iCal feeds.
For synchronization, I'm using iCal as the integration point. I still have a fluid application that now points to my ThoughtWorks calendar, but I'm using iCal as the main calendar. Of course, iCal synchronizes nicely with the iPhone. Before moving back to iCal, I was using CalenGoo on my iPhone, which is a slick iPhone interface directly to Google calendar. It doesn't really provide off-line access but does cache the previous results so you can see your calendar even if you can't get to it online. The native iPhone calendar application handles that for me now.
ToDo / Task List
If the calendar is the easiest, this is by far the hardest slot to fill. Virtually all of the To Do / Task List applications I've used are seriously deficient in one way or another. Ascend replaced the Palm ToDo application (which was laughably bad) with one it called Task List, which was quite good. One of the killer features I need is a start date in additional to a due date (they all do due dates, but most don't handle start date properly). I have a fair number of tasks that I don't need to see right now, but I don't need to find out about them the day they're due either. I need a system that allows me to express "this thing is due on 11/5, but start pestering me about it on 10/30". I also want a tag-based system using contexts, one of the really nice refinements to come from the Getting Things Done cult, rather than a hierarchy of folders.
My research in this area eventually led me to OmniFocus. I say "eventually" because I recently went through this category of application again. I started with OmniFocus but found it too complex for my day to day usage, which led me to Things. I like Things because it is so radically simple, but that became a bottleneck for me because of the way I like to attack projects. That in turn led me back around to OmniFocus and some concentrated learning about how it wants to work. It's heritage is OmniOutliner, and you can still see that lineage, which adds some complexity to some parts. Because OmniFocus has lots of ways to get information into it, I kept misplacing stuff. The thing that took OmniFocus from "nice but tolerable" to "can't live without it" is the custom perspectives. OmniFocus allows you to save customized views, including filters, columns, etc. I created a bunch of custom perspectives that show me exactly what I need ("what things are coming due within the next week", "what needs to be done next on this project", "I have 10 minutes at home -- is there anything that can be done here and now?") and assigned those perspectives to hot-keys using the standard Mac feature of assigning keys to menu items (each perspective shows up as a menu item, making this possible). Now, I never use the built-in views, I always use my custom perspective depending on the information I need right now. Since doing that, OmniFocus has worked fantastically. It allows me to organize my days and weeks, just shows me what I need right now, and I'm confident when I add something to it that it'll appear at the right place and time. Learning to use OmniFocus right was the key, and now that I have I think I have the best task list stuff that I've ever had (beating out Ascend for this title is no small feat).
Of course, OmniFocus syncs with the iPhone (and has a terrific iPhone application) so that I can keep all my To Do stuff with me at all times.
OmniFocus is great for tasks that have firm due dates and works for recurring tasks as well (including some nice flexibility around "schedule the next one of these 5 weeks after the completion of this occurrence", which is great for things like haircuts). However, I have a few but important categories of things where I want to define rules like "I want to post to my blog every 9 days or so", which could be rewritten as "remind me after 7 days that I need to post a blog entry, and start yelling after 11 days if it isn't done". I use a highly specialized tool for this called Sciral Consistency. That's all this tool does: allows you to set up ranges for things that need to be done and remind you.
I could almost replicate this using OmniFocus features, but I already had Sciral and I like the minimal display & single-mindedness of the tool. This doesn't synchronize anywhere, but I always consume this information at my computer anyway.
The combination of calendar and OmniFocus handles all the structured stuff -- what about unstructured notes? I have two mechanisms for that: Evernote and Moleskine.
Evernote is a desktop, web, and iPhone application that allows you to capture notes (organized into notebooks) for whatever information you want to keep and search. A few killer features for me:
- Automatic synchronization always everywhere. Every time you capture something with Evernote, it automatically synchronizes across all views.
- OCR for white board text. I tend to draw on white boards a lot, and if you capture the drawing with Evernote's picture note, it will allow you to do text searches in the web and desktop client for words in the white board drawing. It's not perfect but surprisingly good at this.
- Automatic forwarding address. Evernote sets up an email address for you; anything you forward to that address becomes a notebook entry. This is nice because it allows you to get stuff out of your email client. Evernote has much better searching capabilities than most email clients, and having the forwarding address means you can get searchable emails into Evernote very easily. This is particularly nice for those who use their email inbox as the world's worst filing cabinet; get that stuff out of your email client and into something where it can be useful.
The only bad thing about an entirely electronic PIM: there are still times when you cannot use it (like when the plane it taxiing). This may not seem like a big deal, but I find that I have lots of capturable ideas at exactly the times when I can't capture them. Thus, my other permanent GTD accessory is a soft-sided Moleskine book along with a Fisher space pen. I capture interesting ideas as soon as I have them (because ideas, especially those from the right brain, are fleeting). Once I get back to my computer, I transcribe the Moleskine notes into the rest of my system. At any given time, I usually have a page or so of new stuff in the Moleskine. I could get by with a few index cards but I've been carrying the Moleskine for a while and I'm used to it.
Tying It Together
My PIM lives between 4 different applications and a notebook with no real built-in integration between them. I always use them as a unit. For example, I have all 4 applications bound to the same desktop in Mac OS X, and those are the only things bound to that desktop. That allows me to always leave them in the same window state and position. Anytime I switch to one of the PIM applications, it goes to the appropriate desktop. I've also used Automator to create a PIM application that performs "Launch Application" for each of the 4 that make up my PIM. I no longer think about these applications as separate things.
PIM as Life Support for Focus
Obviously, this system is highly customized to me and won't work without changes for anyone else. I think that it is every knowledge worker's responsibility to find a system that allows them to get to and stay in flow as much as possible. Any tools that you use should make it easier to get to flow, not harder. I find that I tend to work best in 2 hour chunks (which I'm calling work blocks), which is similar to the very popular Pomodoro technique. One of the custom views in OmniFocus allows me to review projects that have pending work blocks so that I can find out what I need to work on, then immerse myself in that problem for a contiguous chunk of time. Whatever system you find, make sure that it supports how you want to work. Don't change your effective work habits to conform to some tool's vision of what your day should look like.