I'm contributing to the Wilson O/R Mapper project which is now open source and on google code. I'm adding fluent mappings for WORM in the same manner as Fluent NHibernate. Exciting stuff!
http://code.google.com/p/wilsonormapper/source/browse/#svn/branches/FluentMappings/Wilson.ORMapper/FluentMappings
Read the complete post at http://dotnettricks.com/blogs/craigbowesblog/archive/2009/01/07/737.aspx