I love my Blackberry but I hate its organizer. For that role I much prefer a Palm device. Anyway, without a good PDA lately I’ve been running around with a ton of open loops, which is bad.
[ UPDATE 2015: I’m still using this system now, 10 years later, but I also use Apple Notes as a digital note taking system. Nothing compares to quick analog text or diagrams, though, which is why I keep my notecards and space pen with me at all times. ]