If you've ever tried to design a new database diagram and gotten a "cannot create objects" error, you've probably noticed the correction steps to use the ALTER AUTHORIZATION statement to change the owner.
This happens a lot to me - I'll be on the corporate net when I create a database, and my domain account will own the DB. Then I leave the net and when SQL Server tries to determine my account credentials, it can't reach the domain to do so.
The fix is easy - I just change the owner to SA. But that's on test databases only! Don't do this if you plan to take the database back to your domain. You'll potentially break things that are depending on that ownership value.