The domain name does seem to help a little. You can try changing the www part to a keyword if it's not too long and doesn't interfere with your business. But the most important 2nd part is to make sure that the sites linking to you update their link. If you're already in Yahoo and Dmoz with the existing URL, you may just want to pass this up. A better strategy is just continue to go out and find better sites to get links from.