[davesmylie]

This isn't an overly easy question - a domain name is an incredibly important part of any startups identity and there's a ton of factors you need to consider above and beyond the obvious SEO factor of having a product related site name.

For me personally, just as important as having a name that relates to what you do, is having a name that is pronounceable (and spellable) via verbal communication. Particularly over a phone line when giving out email addresses etc, when the sound quality may be less than perfect.

There's definitely a shrinking pool of .com names available, but there is still a huge number of names available. I'd be pretty hesitant to go for a domain name that didn't match the startup name.