Flickr Creative Commons – Searches flickr for images you can use.
Free Photos Bank – You can download as JPG or a Zip file
FreeDigitalPhotos.net – Thousands of Royalty Free images ready for instant download.
MorgueFile - The purpose of this site is to provide free image reference material for use in all creative pursuits.
PD Photo – Free photos and pictures, especially of locations.
Stock.xchng – Free stock images – must have a free account to download.
Microsoft Clip Art for Schools
Microsoft Clip Art for Holidays