Here's how you can quickly filter Google's image searches by usage rights. This can be a big help if you are looking for images to use.
1. Do a Google image search.
2. Click the Search Tools box at the top of the page (next to More).
3. Click on Usage Rights.
4. Click your preferred filter, you can choose from the following options:
Not filtered by license
Labeled for reuse
Labeled for commercial reuse
Labeled for reuse with modification
Labeled for commercial reuse with modification
5. Your image search will then show only the images with your preferred usage rights.
Looking for an image online that you can legally and safely use on your own Web site? Google now makes it easier to find one. A new Usage Rights filter is now easily accessible on your search results page, as tweeted by Google software engineer Matt Cutts.More at CNet
Additional resources for Google Image Search