Moving a Solid

 From:  jetblast
6432.1 
Hi,
I've been playing with solids and the Boolean operations. I've been working in the 3D window and managed to move one solid away from the other. How can I bring back that solid back exactly into position so that I can join them ? Redo doesn't do the job and I didn't save.
Is there a point to point or a face to face type of command?
Thanks for your time.