We have seen many MP3 wrist watches which also let you store digital files via USB interface, how often do you see a wrist watch that lets you play video files? Thanko has a MP4 watch on their web based store, supporting video playbacks in MP4 (NXV) format, as well as audio playbacks in MP3 and WMA formats.

The MP4 Watch weighs 50 g and comes with a 4cm x 4cm, 260K color OLED screen with resolution of 128×128 pixel. It comes with either 1GB or 2GB built-in memories which is good enough for 500 MP3s, 10 full-length MP4 movies, or 76 music videos (for the 2GB version). Other included functions are photo album with manual display and automatic slide mode, voice recording, and common watch functions.
Retail price for the MP4 watch is 18,800 Japanese Yen (US$162) which is a little pricey for the tiny screen. It comes with few accessories including USB cable, AC adapter made for recharging via USB cable, earphones, and a CD containing the NXV convertor which converts AVI, WMV and MPEG video formats into NXV format.
Link:
MP4 Watch Product Page