Playing with Visual Studio 2008 Database Edition i ran into the error:

You have insufficient permissions to create the database project.  For more information see the product documentation

I remember in Visual Studio 2005 running under Admin was required for Windows Vista but we shouldn't be needed in Visual Studio 2008! 

After a little sleuth work turns out Gert  aka Data Dude already has a post on this exact topic!

Can you use Visual Studio Team Edition for Database Professionals running as a normal Windows user? Yes!

To summarize his post you need to do the following:

1. The user needs a SQL Server login
2. The SQL Server login needs to be a member of the build-in dbcreator role
3. The SQL Server login needs to be a member of the build-in securityadmin role
4. The SQL Server login needs to have the VIEW SERVER STATE privilege granted
5. If running 2005 SP1, Grant the public group execute rights to the sp_detach_db procedure