The other day while wandering through the Home Depot I happened upon a tool that when I saw it my first words were "Well it's about time."
It is called the Brutus 10in contour gauge, and its used to duplicate the shape of an item and then you can transfer that shape onto another surface.
For those of you who have done any tile work, you might be able to appreciate the tool. In the past when ever I have to cut around a pipe in the floor, or a toilet drain, or some odd shaped corner, I have pretty much just guessed the best I could and then fixed my mistakes with grout, or caulking.
Now that I found this tool I won't have to guess anymore. All you have to do is push it up against the odd shape and then use it as a template onto the surface you are cutting. It's genius, and like I said before "What it's about time."
For more information see: Brutus Contour Gauge at the Home Depot.