This is not an officially supported scenario, but does work, and may be useful for some of you who don't have the resources to create user administration tools right off the bat. There are security implications when doing this, so you need to verify that this is a valid scenario, and that there are no other work arounds available to you.
The biggest problem that I ran into when trying to set this up on my system was file locking. I copied the mdf file over to the wwwroot dir, and it was still locked when I did that, so things didn't work right. Once I got the locking issues taken care of, I was golden!