iStockphoto - Millions of affordable, professional and simply beautiful royalty-free photos, illustrations (vector art), video, audio and flash. 

- Bigstock boasts over 4 million royalty-free photographs and illustrations (vector art) from talented photographers and artists around the globe, available for almost any purpose.

 - Fotolia is the first worldwide social marketplace for royalty free stock images, allowing individuals and professionals to legally buy and share stock images and illustrations. Fotolia offers the largest image bank of free and affordable royalty free photos and illustrations perfect for any medium, web or print.

Photographers and designers constantly update Fotolia with thousands of new photos and illustrations each day, while photographers and designers receive commission from each photo sold and revenue from advertising on the free section.

Please Note: Make sure you read and understand the licenses for use, terms & any legal notices on the websites listed above before buying and using royalty-free images, audio and flash files.