Wikipedia Article

http://en.wikipedia.org/wiki/Comparison_of_smartphones

Android documentation on  multiple screens sizes

http://developer.android.com/guide/practices/screens_support.html

Screen Resolutions for iPhone

Full Screen - No top or bottom bar. (phoneGap view) - 320 x 480

Almost Full Screen - Standard top bar - 320 x 460

Mobile Safari View - 320 x 414 (20 on top & 44 on bottom for nav buttons- Imagine tapping the Safari icon, then browsing to a web page)

Android

HTC Android G1

Full Screen - No top or bottom bar 320 x 480 (320x465 when the status bar shows)

Motorola Droid

Full screen: 480x854

LG GW620 Eve

disaplay: 320 x 480 px, 3.0 in 

HTC EVO 4g

Full Screen: 800 x 480