At the beginning of Lucky Star 16, we get to see Konata playing around with her keitai. It's almost certainly the Sharp SH903iTV. TV, of course, stands for television (hence the swiveling screen). Apparently, watching wireless digital broadcasts while commuting has become popular recently.

Rundown of the basic specs:

Width: 50mm
Length: 111mm
Weight: 143g
Displays: 3.0" Main LCD, 0.8" Sub LCD
Cameras: 2.0MP main camera, 0.1MP secondary camera (video conferencing)

It also has a built in FM transmitter (for the car), a DVR mode for recording broadcasts, and a whole list of neat features that are pretty much standard on Japanese phones these days. Meanwhile, my phone is 4 years old and was obsolete when I got it. It can hardly make calls these days. I need a new one...

More Details (Japanese)