Free Sound - The Freesound Project is a collaborative database of Creative Commons licensed sounds.
Free SFX - Free sound effects and music for multimedia projects.
SoundJay - Free sound effects for use in projects.
SoundGator - Free, downloadable recordings of common sounds like doorbells, dogs barking, car horns honking, etc. Browse 23 categories of sound.
Creative Commons - Search for images, video, and music using various directories, including Google, Yahoo, Flickr, etc.
Wikimedia Commons - Freely usable media files - images, sounds, video, and more.
Veezle - Veezle searches only FREE stock photo websites. Each image is accompanied by clear information on how the image can be used, along with code to easily embed the image in web pages, blogs, etc.
Wylio - Designed for bloggers, Wylio is an image search engine that searches Creative Commons images. Wylio automatically sizes the image, hosts the image, and builds the photo credit into the code.
MorgueFile - MorgueFile contains free photographs for use in creative projects, contributed by professional artists. This site also links to Dreamstime, a paid stock photography site. Registered Dreamstime users get a small amount of credit to access a few images free.
Public Domain Sherpa - This site provides information on copyright, focusing on media (books, maps, photos, sound recordings, etc.) available in the public domain.
Pixabay - Thousands of high-resolution public domain images searchable by keyword or browseable by category.
ClipArt for Google Docs - 4 ways to responsibly integrate clipart into your Google docs
Public Domain Review - Focus is on works which have now fallen into the public domain, that vast commons of out-of-copyright material that everyone is free to enjoy, share, and build upon without restriction. Our aim is to promote and celebrate the public domain in all its abundance and variety, and help our readers explore its rich terrain.