Linux-friendly PDA?

[Kirk Bridger]

Happy holidays everyone,

I'm starting to look around for a Linux friendly PDA - one that ideally 
runs Linux (or can be hacked to do so), or at the very least can operate 
using Linux as my only OS.

By PDA I mean something that can:
- keep a list of tasks, categorized (e.g. tags)
- keep a list of calendar appointments (ideally that associate in some 
way with the tasks)
- connect and sync with a web-hosted calendar (calDAV or ICal I think 
are the terms)
- connect and sync with an LDAP address book
- IMAP mail syncing
- touch screen
- small enough to carry with me
- lots of battery life

Things I don't really need, but might be nice
- Bluetooth


Things I don't care about
- media playing
- phone features


Anyone have any experience, good sites to read, or success/failure 
stories?  I'd love to hear them!

Thanks all,

Kirk