Seeing as how I've made it my personal goal to obtain the "thinnest" electronic devices possible, I suppose I should add Alpha Data's new "AD-OFMS" mobile mouse to my list. It's a USB optical rollerball (uses an optical sensor to pick up the movements of the roller) mouse that stands a mere 15.5mm high -- not sure how comfortable that would really be o­n the hands, but hey, you can't have everything.

Alpha Data Corporation will release the "AD-OFMS" optical mobile mouse with scroll wheel in late July. It is Open Price, but estimated at around 2,500 yen. Supported operating systems are Windows 98, Me, 2000, and XP (translator's note: the original article omitted XP, but the specifications list XP as being supported so we'll go with that...) as well as MacOS 8.6 and above.

The OFMS is a 2-button wheel mouse with a roller (both horizontal and vertical) that is read by an optical pickup. The roller is quite light at o­nly 0.5g, which helps prevent slipping when starting to move the mouse, as happens with ball mouse that have heavier balls.

Also, while typical optical mice take readers at a rate of about 1,500 per second, the OFMS will take readings at a rate of roughly 12,000 per second -- this allows for detection of quick movements, so even with its particular style, it can be used easily.

The body size is 47 x 80 x 15.5mm (W x D x H), and it weighs about 61g. The resolution is 625dpi. Its interface is USB, and a pouch for storage is included.

Inspired by:
http://pc.watch.impress.co.jp/docs/2005/0719/alpha.htm

Product Information:
http://www.alpha-data.co.jp/products/mouse/ofms.html