List of popular free photo websites
Flickr Creative Commons — also searchable via Compfight or photopin
[photo count: 85M+]
[photo count: 85M+]
freeimages [407k+]
(was sxc.hu or Stock.Xchng)
morgueFile [225k+]
stockvault [46k+]
openphoto [est. 20k+]
picjumbo [##]
freerangestock [##]
imagebase [##]
Oversimplified explanation of photo use licensing —
Creative Commons = use photo with link to photo credit for attribution
Public Domain = use photo any way you’d like, no attribution required
more free/paid photos at dreamstime.com and fotolia.com