If you're looking for project components and you can't dig them out of leftover hardware at home, here are some suggestions. Please add more as you think of them.
American Science and Surplus - www.sciplus.com - An ever-changing selection of batteries, motors, optics, discontinued toys, and other miscellany. Everything from $2.00 bags-of-thingies to $100 military surplus tank optics. I've ordered from them several times and they've always been prompt. They also publish a hardcopy newsprint catalog.
Overstock.com - www.overstock.com - a member at the 9/10 meeting found a bulk pack of 6 Mattel Juice Box video players for $26 - a device that can be hacked to play standard flash cards and run Linux. (http://www.overstock.com/cgi-bin/d2.cgi?PAGE=PROFRAME&PROD_ID=2039880)
Kmart - www.kmart.com - watch the Clearance section, and you might see a good deal like a R/C toy helium blimp for only $15.
eBay - I've only checked for electroluminescent cabling and kits, but I've seen some good prices on those. Hit or miss, buyer beware.
also www.allelectronics.com is a good source for electronic/mechanical surplus. -hro