I think all of us always try to get nice, interesting pictures either for collection or for desktop background. You crawl on web like Google in search of nice pictures. When you grab one, you don’t know if its copyrighted or not! But you can always grab all the best pictures posted into your mail box just for free.
Everyday they select a picture as Picture of the Day based on community feedback from a verity collection of pictures. All the pictures are licensed under GNU Free Documentation license, which mean they are free.
Wikimedia Commons maintain a mailing list to get picture of the day into your mail box. Just click on
You can also subscribe to their feed: