Mobile Design Dimensions

Resolution
Devices

320×240

• Blackberry Devices: Curve 8530, Pearl Flip
• Android Devices: Motorola Charm, Sony Ericsson Xperia X10 Mini, others
• Symbian OS Devices: Nokia E63, others

320×480

• Apple OS Devices: iPhone, iPod
• Android devices: HTC Dream, HTC Hero, Droid Pro, i7500 Galaxy, Samsung Moment, others…

480×360
Blackberry Devices: Torch, Storm, Bold

360×640
Symbian OS Devices: Nokia N8, Nokia C6-01, others

480×800

• Android Devices: Liquid A1, HTC Desire, Nexus One, i9000 Galaxy S, others
• Maemo (Linux) Devices: Nokia 900, others
• Windows Mobile 6 Devices: Sharp S01SH
• Windows 7 Phone Devices Venue Pro, Samsung Omnia 7, HTC 7 Pro, others

768×1024
iPad

640×960
iPhone 4

1280×800

• Android Devices: Motorola Xoom, Samsung Galaxy Tab 10.1
• Windows OS Devices: Asus Eee Pad EP121
• Apple OS Devices: Axiotron Modbook

Please note that this is a very limited list, and is by no means complete. What is important to take from this data is that a wide range of screen resolutions are out there, and new devices are introduced constantly.