use-logical-naming-conventions.jpg (keywords), throw in a keyphrase in the alt attribute and get some keyphrase-rich textual content nearby.

yOu can build backlinks for images also by posting them in forums.

You'll not get great results with just optimised images, you need to look at the page content as a whole.

I wrote a couple articles on image SEO, feel free to take a look,

http://www.ginside.com/2006/383/seo-tips-image-naming/
http://www.ginside.com/2007/993/seo-...aming-round-2/

I think adding "alt" attribute is also helpful in image.

Very Important Factors

1.) Use keywords in the file name of the image, such as red-widget.jpg.

2.) Make sure the image has a caption, preferably in bold, immediately above or below the image, with the keyword(s) you’re targeting.

3.) Also use the keyword(s) immediately before or after the image in the main body text on your page.

Less Important Factors (but possibly helpful)

4.) Alt text and Title element used on the image. (I’m actually testing this a bit at the moment.)

5.) Anchor text of any links pointing at the image.

6.) Trust factors (i.e., site trustworthiness, age, etc.)