SQL Server 2008 and extended properties In SQL Server, what do you guys use extended properties for? Some articles and blogs are suggesting they be used for self-documentation of the database and its objects but I can't see this being used properly... is this largely ignored by most?
Largely ignored, as you're saying.

Extended properties are a bit awkward to read and write both from T-SQL and GUI. IMHO documentation should be maintained elsewhere (database projects, project documentation etc.).

Here's a good article on extended properties, which also addresses some of your doubts.