There are piles of free clipart and photos available on the Web. The biggest problem is the time it can take to find what you want. The collections designed for teachers are the most useful but are fairly limited. If you or your students have any intention of publishing projects using these pictures be absolutely sure that they are royalty/copyright free!
Creative Commons Creative Commons is a nonprofit organization that enables the sharing and use of creativity and knowledge through free legal tools. It gives copyright licenses to provide a simple, standardized way to give the public permission to share and use creative work.
Artvex.com Good collection organized by categories
CAPL Culturally Authentic Picture Lexicon Select by language
Clipart Links for Busy Teachers From The Canadian Association of Second Language Teachers.
Clipart Review Links to many clipart sites
ClipArt ETC Over 60,000 pieces of free clipart with a friendly license for teachers
DHD Multimedia Gallery Original stock photography, clip-art, sounds and video clips
Discoveryschool.com Clip Art Gallery Pictures for teachers.
Finding Public Domain Images for Multimedia Projects edtechteacher, 21st Century Learning
FreeFoto.com Mixed bag of photos. Try the food and weather categories.
Google Image Select "Image" and type the word you want. Be prepared for thousands of responses. It’s overwhelming, and most are completely useless for our needs, but you can sometimes find the perfect picture. You can search by type (photo, clip art, line drawing), color, and size. Pay attention to the size of the image. If it’s too small it won’t look good if you enlarge it for a PowerPoint or to show to the class.
Indezine Links for free images.
LanternFish Good flashcards, mostly in English but some in French and Spanish. The English flashcards can be adapted to other languages.
Microsoft Office Online Clip Art and Media Excellent collection. You can search by type (photo, illustration, sound, animations) and size.
National Geographic They have Photos of the Month and weekly wallpaper downloads. Look through the archives, and you may find something you can use. In any case, they’re great pictures.
Pics4Learning Large collection, mostly photos
Royalty-Free Clip Art Collection for Foreign/Second Language Instruction Line drawings developed at the Japan Project at Purdue University. Good for any language.