We (ok the company where I work) just got one of
these beauties.
To my surprise - it runs on Qtopia. As soon as the new wears off a little and it has fingerprints from all the other network geeks in the shop - I'll dig into it a little and get specifics. All I know so far is the screen is about 4 times as big as my 6k and the wireless features beat the crap out of kismet... Haven't seen it on copper or fiber - yet.
It does still have the calendar app, most of the "control panel" type apps, a linux console and a version of Konqerer on board. Came with a USB keyboard too.
A little pricey for a PDA though at roughly 18k - USD.