Depends on what you used to root it, etc. One thing I did with my new one though, is as soon as I unlocked it, I made a "stock" nandroid, so that if I ever need, I can put it back to the way it was on day one and then just relock it. I know it doesn't help with your situation atm, but it might come in handy later.
If you've got Wugs Toolkit, you should have an option in there to return it to stock through that, if I remember right.