Here's one way,
Step 1: Make sure both objects pivot are centered. Just select an object and then goto Modify->Center Pivot.
Step 2: Select Sphere and Cube and then goto Display->Transform Display->Rotate Pivots. If you goto wireframe mode, you will now see little circles inside your objects.
Step 3: Select the sphere. Now hold down the "v" key and middle mouse move on the rotate pivot of the Cube. Your sphere will now be in the exact spot as the cube. To turn off the rotate pivots, just select the objects and goto Display->Transform Display->Rotate Pivots.

Have fun!

You could also use the transform settings in the channel box but if you've frozen transformations on anything it wouldn't work.