The Nudge tool in Revit is one of my favorite tools.
After you have placed an element and want to move it but don't want to type in distances use the Nudge tool.
The arrow keys allow you to Nudge the element, left, right and up and down. The distance that the element moves with each nudge is determined by your zoom scale, the closer in you are the smaller the increments and the further back you are the greater the distance the element will move.
you can also use SUPER NUDGE by holding down the shift key while nudging, this will increase the Nudge factor by x10.
I love the word NUDGE!