On Tue, 2008-01-29 at 21:15 +0000, Jan T. Kim wrote:

I'd like a handheld of some sort that

* interoperates with Linux (the Palm can be backed up and restored
  using pilot-xfer, but I've not found anything useful to work with
  the data in the *.pdb ("Palm Database") files)

I haven't had a Palm since my Treo 600 died but wouldn't http://www.jpilot.org cover this if you buy another Palm device ?

* is small (the Zaurus SL-C palmtops seem interesting to me in many
  ways, but I think they're just a bit too bulky for shirt pockets,
  and also, they're quite expensive)

Again the last Zaurus I played with was the SL-5000 and as great a geek toy it was, the PIM apps were very much lacking compared to even the early Palm stuff. Linux PIM sync was not possible and even getting access to the device to transfer files took some fiddling. Some of these things may have changed or improved since the SL-5000. As a highly portable linux box it worked well in a niche now filled by things like the EEE PC, as a PDA it was pretty weak compared to a Palm IMO.

Oh and battery life was poor.

* provides a decent choice of software for contacts, diary keeping,
  and (ideally) an advanced "To Do" tool that understands dependency
  graphs and integrates with the diary

Any recommendations / experiences / comments? Please let me know.

I am afraid after the Zaurus I got on the convergence bus and now use my phone to organise my life. But it seems to me that if Jpilot does the job regarding desktop access to the PIM data then another Palm device would be the best way forward for you. Either that or get on to your mobile provider and see if you can get a good deal on a Nokia E90 (which can with some fiddling be made to talk to evolution for desktop syncing purposes)

The convergence bus for me was the kick I needed as before the PDA devices sat in the glovebox of the car most of the time and therefore were never on my person when I actually needed them. It's a compromise (not a big one in the case of an E90) but one that has worked out very well for me.