I've used most every gadget and doo dad out there. Very few are in my permanent and regular rotation. Of those:

iPod - greatest thing since sliced bread. I have a 10Gig version that stays in the studio and a 20Gig that goes everywhere with me. I currently have over 1200 songs on it, and also use the HD feature to transfer ProTools sessions between various machines. I recently got the rev3 model, and have some issues with the new ergonimics.

Palm Tungsten T3 - I can live without it, but the alarms come in handy. Grafitti v2 blows though...I don't make "T's" like that...

HP iPaq 2215 - Yes, I generally hate all things MS, but this is great hardware, and the handwriting recognition works almost as well as the last iteration of the Newton. I find this useful for writing lyrics and notes. The calendar isn't as elegant as Palm, but what are you gonna do?

Motorola V60i - I like Moto phones...and the V60 is small enough to carry in my pocket (my wife thinks I look too much like a tech geek if I wear it on my belt).