<a href="http://msdn.microsoft.com/asp.net/using/building/web/default.aspx?pull=/library/en-us/dnaspp/html/URLRewriting.asp">this msdn article on URL Rewriting</a> is quite handy. see, my site uses these a lot and since im thinking of moving to ASP.NET to run this site, having URL rewrites may be a handy idea. makes the migration from one blogging system to an other a lot easer. check out the article though.