SpudFiles

17mm x 17mm x 8 mm, 5v

Copal PN: f17ha-05mc

Available through Digikey

Nice find. A bit pricey though at $13.30.

Here's one that is almost as small (25mm square x 10mm thick) for $2.50.

If you want really, really small fan then this one is 4mm diameter x 8mm long (~3/16" x 3/8") for $1.25. Just grind the weight into a rough fan shape, or replace it with a homemade plastic blade.

http://www.goldmine-elec.com/

that is whare i get all of my electronic components