Sometimes there’s no “backsies”. If you’ve posted or printed something wrong there’s no going back. Anyone who’s worked with shortening URLS has done this one time or another.
The major URL shortening services DON’T give you the power to go back and revise a URL that you’ve gotten wrong. 2vu.me does.
If you’ve gotten a URL wrong and need to change the target page 2vu.me can do it.