Let me pass on an old trick that I learned years ago with dents in furniture. I might help you get a very minor indentation out of your guitar if you hit it somehow. But be very careful and take your time. Just heat up your clothes iron and place a thin wet towel between the iron and the dent. Give it several short contacts and see if the wood might steam back to it's original shape. It can at least make it better.

A soldering iron and a thicker moist towel gives you better control, lets you get into areas where a clothes iron won't fit, and limits the heat and steam to the dent.

It works pretty well if the finish has cracked or chipped and the steam can get to the wood. Sometimes it'll help even if the finish is intact, but a dent in thick poly is usually there to stay.

Here's a tutorial from a great repair site:http://www.frets.com/FRETSPages/Luthier/Technique/Finish/SteamOut/steamout1.html