I am still using an old Cingular 8125 (HTC Wizard)
If I were to upgrade my phone I would consider an
HTC Advantage X7501 They have a large, Crisp screen and can be had for $350 - $450 unlocked.
I plan to go for a UMPC in February, just to be able to do more than read and play music better. Probably a
Fujitsu U820 - U810 or an
HTC Shift.