Yep - we have been down this path and have actually achieved it using real .Net enums (as used in our app) within SQL Serevr 2005.

We use an excellent, i.e. this is the best thing since sliced bread and cold beer!, product called StrataFrame and the use of enums within SQL Server 2005 was put to their (again excellent) support team and they came back with the following:

http://forum.strataframe.net/Topic10664-14-1.aspx

It took a little bit of messing around but, in the end, it works like a charm.

Cheers, Peter