How do I "mv */* ./" in a Windows command shell?

On a Windows machine, I've got about 50 subdirectories in the same directory, each with around 5 files in it. I want to get all 250-or-so files into one directory.

In a UNIX system, I'd just open a shell, type

mv */* ./

and be done with it.

I don't know how to do this in Windows. move */* ./ doesn't work.