This video shows how to call code in your databindings to do some funky formatting.  Here I have nested a datasources inside a datalist.  I show a price as crossed out if there is a sale price.

http://davewebster.members.winisp.net/catdetails/catdetails.html

Note that you can do more than just calling Eval() in those custom dabinding statements.  Also there is a warning on use of the aspx Culture tag.

Enjoy.