Cool tool for the 1940s census

I just found a tool that can help with the 1940s census. As you probably know, the 1940s census will be coming out on April 2nd. They will be indexed by enumeration district, but not by name. It will be a while before it will be indexed by name.
If you are like me, you do not want to wait. Stephen Morse has made a cool tool that can help with that:
All you need to do is list the state, town and street address. From that it can give a (or a few) enumeration district. Yay!