There are lots of web resources that allow researchers to view pictures (images), movies, and sound. The web sites that allow researchers to view movies and sound are www.altavista.com and http://go.grolier.com
The web sites that allow you to view just images are as follows:
Microsoft Design Gallery Live - http://dgl.microsoft.com/
The Amazing Picture Machine - www.nctec.org/picture.htm
Google Images - http://images.google.com/

There are a BUNCH of web Resources listed on the Multimedia Madness website: http://www.wtvi.com/teks/mm/default.htm#imagesources

*Images are great for visual aids for students and also to do creative posters and presentations!