If you're talking about Domain Names (and I assume you are considering the forum) many registrars will tell you what's available or suggest alternatives. For example, I use a particular registrar to REGISTER my .COM names, and if the domain isn't available they give a long list of alternatives.
edit: deleted the obvious.
(edited by: hasbeen at 9:05 pm (utc) on April 3, 2002)
I am currently building one, depending on how complex it is, these scripts are not the easiest thing to do. First you have to find a good meaning based dictionary that links to other similar meanings. That would be the foundamental building block. If anyone has a good building block like that let us know.