It depends on your screen resolution :

• 480*320 for devices like the HTC Wildfire (QVGA)
• 800*600 for devices like the HTC Hero or Legend (HVGA)
• 800*480 for devices like the Nexus One (WVGA800)
• 950*586 for devices like the Motorola Droid (WVGA854)

It depends on your screen resolution :

• 480*320 for devices like the HTC Wildfire (QVGA)
• 800*600 for devices like the HTC Hero or Legend (HVGA)
• 960*800 for devices like the Nexus One (WVGA800)
• 950*856 for devices like the Motorola Droid (WVGA854)

edit : in fact some of this dimensions work but are not the correct ones (they fit because of the same aspect ratio). Matt's answer is better !