I think the fan you are looking for is similiar to this

http://www.jameco.com/cgi-bin/ncomme...nbr=501&ctgys=


These fans are all 5V fans but most are larger than the tiny one that associated uses.

http://www.jameco.com/cgi-bin/ncomme...rch=FAN%2C5VDC

Perosonally I use the 1.6" sq size fans and they work well.I use this one

http://www.jameco.com/cgi-bin/ncomme...nbr=501&ctgys=

it is on closeout, so they may not be there long.