Client-side data manipulation

Finally started to play with XML and XSLT, using it to manipulate some data about some human cannonball performances (a whole other story). I've never had the chance to work (in-depth) with ASP, PHP, or any other database-driven, server-side language, but using JavaScript to access the XML-HTML parser in IE 5+, I was easily able to do some pretty impressive data manipulation on the client-side.