I found this article by Jacob Gube today on a Linkedin group I joined called Communication Arts (posted by Will Sherwood) about 12 great tools for deciding on a website domain name.

It is a very important step in developing your business or project and it is often one of the most difficult. Every time I try to find a domain name I feel like every pronounceable combination of letters must already be taken! These tools could really help you.

You can go to the article and read more about them as well as going to the links and seeing what the developers have to say about them.