1. Flickr: Be sure to use specific search tools for Flickr, however, instead of searching the main website!
1. Compfight (searches Flickr Creative Commons - be sure to turn Creative Commons ON at the top)
2. Flickr Creative Commons Attribution-Only Search
3. FlickrCC Blue Mountains Displays attribution
4. Flickr Free Use Photos Photo sharing, no attribution necessary
5. Flickr: The Commons (contributions from major institutions)
6. Library of Congress Photo Stream on Flickr Goals--To increase access to publicly-held photography collections and to provide a way for the general public to contribute information and knowledge. (Check for licensing on individual images.)
2. Creative Commons A multimedia CC search, searches across Google, Flickr, Yahoo!, BlipTV, SpinXpress, and OWL Music Search, allowing searchers to specify a search for media to use to modify or for commercial purposes
3. WikiPedia
1. Wikimedia Commons: A database of 14 freely usable media files to which anyone can contribute.
2. Images by type
3. Wikimedia Commons-Images-Science
4. Wikimedia Commons-Images-Nature
5. Wikimedia Commons-Images-Society

Secondary Recommended Sites

1. Copyright-friendly images and sound
2. 4 Free Photos Free images under Creative Commons license.
3. Public Domain Images Several thousand royalty free stock photos nicely organized in folders, free for personal and commercial use.
4. Flickr's Creative Commons Pool: Browse through the images provided by Flickr users who have chosen to offer their work under a Creative Commons license. A
5. Flickr Advanced Search also allows you to search for these images easily.
6. AlegriPhotos Free photos.
7. Flickr Free Use Photos Photo sharing, no attribution necessary
8. Flickr Storm (select appropriate Creative Common license from pull-down menu)
9. Creative Commons
10. PhotosPD public domain images
11. Free Images Collection No Copyright, High Resolution, Free Images
12. Creative Commons Videos
13. TagGallery (creates a globe of Flickr images)
14. Online Photosharing in Plain English
15. SpringfieldGallery
16. Springfield Clipart
17. Drape's Takes Educator's Guide to Creative Commons
18. Images4Education Ning
19. Photo Tampering Throughout History (for media literacy)
20. Copyright-friendly WebList and Thumbnail list
21. Flickr's Creative Commons Pool: Browse through the images provided by Flickr users who have chosen to offer their pictures under a Creative Commons license. A
22. Flickr Advanced Search also allows you to search for these images easily.
23. Wylio: all-in-one picture finder and re-sizer made specifically for bloggers
24. Flickr Storm (select appropriate Creative Common license from pull-down menu)
25. Beholdcc Use the boxes before you search to select licensing
26. Veezle (free stock photos)
27. Shahi Visual Dictionary (check for licensing, many are CC and Wiktionary)
28. Clipart ETC (University South Florida)
29. openphoto: Free stock images. Use categories on the right to browse or click on search in the top bar
30. BurningWell (public domain, high resolution photos)
31. 25 Free Stock Photo Sites
32. Photl
33. Free Images Collection (No Copyright, High Resolution, Free Images)
34. Wellcome Images (medical and social images)
35. 26 Places to Find Free Multimedia for Your Blog
36. Creativity103.com (abstract backgrounds)
37. Photos8 (public domain photos and backgrounds)
38. OpenClipArt.org
39. Public Domain Clipart
40. Sevenload.com
41. VADS: Free Art and Design Images for Education (Read Terms of Use)
42. US Government Photos and Multimedia Most materials is in the public domain, but read the disclaimers.
43. Yahoo Creative Commons Search
44. Free Digital Photos
45. Pics4Learning Copyright friendly images for education
46. GetMedia
47. MorgueFile provides the public and creative community with free photos..
48. Free Pixels:images may be used for both personal and commercial purposes under the limitations of this license
49. Free Photos Bank
50. stock.xchng
51. PD Photo
52. Public Domain Pictures - high resolution photos and illustrations under public domain license
53. Public Domain Images Public domain images (copyright friendly -safe images), royalty free stock photos. All photos on this site are top quality high resolution public domain images, explicitly placed in the public domain.
54. FreeFoto.com
55. 4 Free Photos - collection of over 700 free images offered by the photographer
56. Free Photo 1
57. OurMedia
58. FreeMediaGoo
59. AnimalPhotos.info
60. CarPictures.cc
61. Images for Education (for UK higher ed.)
62. Black and White Clipart

Other portals (some subject-specific)

1. this is first
2. Smithsonian Flickr PhotoStream
3. PBase World Gallery (amateur photos organized by country)
4. Digital Librarian Images (check for licensing)
5. Flickr-Related Tag Search (not all CC)
6. Free Military Photos
7. GeekPhilosopher
8. American Memory Collection: Library of Congress. (click on "Photos and Prints" and check the "Copyright and Restrictions" section for each collection)
9. American Memory Maps Collection
10. America From the Great Depression to World War II: FSA/OWI 1935-1945 American Memory collection
11. Art Images for College Teaching
12. Centre for Bioscience ImageBank
13. Daguerreotype Portraits and Views 1839-1864
14. Department of Agriculture Image Gallery
15. Department of the Interior Photo Resources Library
16. Graphic Maps.com
17. Great Images in NASA (GRIN)
18. Incomptech - Royalty Free Music; Search by Genre or "Feel" of Music
19. Images of American Political History
20. Internet Moving Images Archive (read Conditions of Use)
21. Metropolitan Museum of Art (Please read copyright info)
22. NARA's Search Tools
23. NARA's (National Archives and Records Administration) NAIL Search
24. NASA Image Exchange
25. NASA Multimedia Gallery
26. NASA's Planetary Photojournal
27. National Health Museum(AccessExcellence)
28. NIH Image Bank
29. National Library of Medicine: Images from the History of Medicine
30. Picture Collection Online (New York Public Library)
31. NOAA Photo Library (National Oceanic and Atmospheric Administration)
32. NOAA - National Marine Sanctuaries Media Library
33. Public Health Image Gallery
34. Picturing the Century: 100 Years of Photography
35. Science Images (Earth Zone)
36. Selected Civil War Photographs
37. Springer Images (scientific images with liberal licensing, read the Copyright restrictions)
38. Training Reference: Images for Learning Materials
39. US Air Force Link: Photos and Art
40. US Fish and Wildlife Services Images
41. US Geological Service Photographic Library
42. US Navy Images
43. USDA Historical Photos
44. UTOPIA (UT Austin) Portrait Gallery (historical figures)
45. University of Cambridge List of Freely Available Images Links
46. EduPic Graphical Resource - Free Photographs and Graphics for Education