If you haven't tried it you should. Many people get a good chunk of their traffic from Google images.

If you are interested in getting traffic traffic from Google Images, here are some tips for you:
- Use keywords on img alt tag.
For example <img src="a.gif" alt="classified ads" />
- Use keywords on image file name.
For example <img src="classified-ads.gif" alt="classified ads" /> is better as compared to <img src="a.gif" alt="classified ads" />
- Make sure your robots.txt does not restrict access to the image folder.