A long, long time ago (2003) in a country far, far away (Japan) NTT DoCoMo introduced the first mobile phone with 3D display. The phone, made by Sharp and known by the cryptic name SH251iS had 2.2 inch, parallax barrier-based 3D display, with the usual for 2003 resolution of 176 x 220px. In portrait 3D mode that makes 88 x 220px for each eye - which even back then was barely acceptable.
Fast forward to present time. In 2009, KDDI Japan offers the "WOOO Ketai H001", which is a mobile phone with 3D display from Hitachi. The specs are up to the standards of 2009 - 5Mpix camera, 1seg TV tuner, and most notably - 3.1" 3D display with resolution 800x480 pixels. The display seems to be switchable, parallax barrier 3D (there is dedicated 3D button under the keypad). In stereo-mode this would result in 400x480 pixels for each eye - much more suitable for 3D video, we would say.
Additional note about the resolution: on the KDDI website (as far as we can tell) the phone is listed as being "…3D 3.1 (inch) VGA…", without specifying the exact resolution. The guys from Akihabara news, which probably know better Japanese than us, suggest it is 845x480. However, parallax barrier usually goes with even number of horizontal pixels. Knowing some 3D displays intended for mobile use, we would expect that 800x480 is the proper resolution. We will post an update as soon as we know the details.