You enter a string that you want included in your new domain name, and domainsurfer reports back a list of all the taken names that include that input string. Just seeing what is already taken, spread out on one big list, can stimulate creative ideas.
Domainsurfer also has wildcard support, and you can anchor your string to the beginning of the domain name, or allow it to appear anywhere.
It's a nice time-saver.