Everystockphoto:
This website offers a combination of free images plus licensed one. It takes images from different images sources. So, if you are planning to use images, you have to check whether the publisher has given you the license to use it free or not.
Visit: http://www.everystockphoto.com/
Ginipic:
Ginipic is a new player and this has taken the image searching to the new level. This not only searches for the images but also different search engines and websites which can offer pictures collection.
Visit: http://www.ginipic.com/