Somehow, I keep coming back to paper.
I’ve had no fewer than eight iterations of various Palm and WinCE PDAs as well as my current iPhone. I’ve tried plenty of task tracking apps on those, on the desktop, and on the web, and I always come back to paper.
The main issue for me tends to be data entry. Quick notes, a quick sketch, a doodle–the iPhone (a slow 3G, no less) is way too slow. By the time I swipe, put in my password, and bring up the relevant application, it’s been 15 seconds and I might as well take the time to properly “file” the thought or task rather than just dropping it into my “inbox”. Usually stuff just doesn’t end up in the system.
Keeping access everywhere drops desktop apps right out of the running. My last system used Remember the Milk, which has an iPhone app and a web version. It was pretty slick, but over-featured, and, again, data entry on the iPhone is too slow.
So now I’m back to my classic notebook. It’s not a Moleskine–who needs that brand loyalty?–but it’s a fuzzy faux-seude and the paper is lightly lined. I use hard plastic tabs to separate contexts/lists (Home, Errands, Phone, Computer, MITs, Books, Projects, etc.). The tabs are good enough that when I need to move to the next available empty page, they peel off and restick just fine without tearing the paper or falling out.
The iPhone is certainly more compact, though. I don’t enjoy adding more weight to my purse, and I’m having to get back into the habit of carrying it around around. But I do enjoy writing with good pens, letting my handwriting or corrections remind me of the details of an idea, and that weird sense of accomplishment that comes with filling the pages of a notebook with completed tasks and ideas. You just don’t get that with a computerized list that keeps itself tidy and sorts itself.