You could also check out the PLINQO set of code generation templates, based on CodeSmith, which allow you to do a lot of neat things for and with Linq-to-SQL:
Check out the PLINQO site at http://www.plinqo.com and have a look at the intro videos.
The second tool I know of are the Huagati DBML/EDMX tools, which allow update of DBML (Linq-to-SQL) and EDMX (Entity Framework) mapping files, and more (like naming conventions etc.).
Marc