I still think my iphone is awesome, admittedly it did get a bit boring, hence me jailbreaking it. But since then its awesome again, about 2-3 new apps every day. Either little fun things (solitaire, NES emu, TTR) or useful things (Email tools, BSD subsystem, SSH). Really cool.
Maybe I just dont pay enough attention but Ive not heard of a booming hackscene on other mobile devices such as windows mobile, Palm or Symbian?
Bit gutted about the rumours of a 3g one coming out in May.. but I wouldnt of been able to afford it anyway (iphone was a birthday present for me).
edit: after writing this i checked engadget and read this:
"Now that the Zune has upped the ante by including WiFi syncing out of the box, it looks like owners of other devices are starting to rig up solutions of their own -- and the iPhone setup developed by eddanx seems to come closest to the ease of the Zune. The system relies on the WinAmp plugin ml_ipod, which supports syncing to shared folders, and requires a jailbroken iPhone and a little SSH / SFTP softshoe. Of course, by giving up iTunes, you give up contact, calendar, movie, and phone syncing as well, but who cares -- youre wireless now, baby. Check the read link for the full instructions."
Link