even easier on a mac
I am guessing you are running OSX, in which case you have either panther or tiger , 10.3 or 10.4

in 10.3, just press Apple + F to bring up the search box, slect the folder you ant to search within and narrow down your search to kind, i.e picture etc

in 10.4 easy, as you have spotlight. Spotlight is the blue magnifying glass top right, or apple + F again. select the folder and narrow the search again

easy