In my manual about starting your own blog I already wrote some tips for choosing a domain name. To help the people that still need that perfect name for their company, application or weblog I have some nice links:

• MyDomain When you search for a domain and it’s no longer available you can click on the “suggested domains” link. You will automatically get a list of domains that are still available and match your keywords.
• DomainNameSoup Here you can find all kind of tools that help you to pick a nice domain. A nice feature is the special page where you can look up a random selection of previous searches which at the time showed up as available.
• Sedo If you have no more inspiration you can always look at what other people are trying to sell. Maybe this will give you some new thoughts about a good name.
• Nameboy You can give in keywords and the site will generate domain names that you can register or back-order.