Username In "Limbo"!

Hi. I was signing up for an account on 12seconds. I hit the wrong button before everything was complete. Got an error message. Went back to redo and now it says "that user name already taken". It is the user name that I use for all my accounts and would like to keep it to be consistent, but I'm afraid it is now lost in limbo without an email attached to it and I can't re-sign up with it etc. How can I reclaim that name and finish doing a proper registration for an account with it?
Thanks... Steven