Most people don't know that Jedi's can become invisible. This is because it wasn't shown in any of the Star Wars movies. Well, it was but probably you couldn't see it because they were invisible. Anyways, as you can imagine it's one of the most useful mind-tricks out there.
Now I can't tell you how it's done, except that it takes a real Jedi Master like myself to be able to do it properly, but I can tell you that there's a lot of practice involved. Mostly in the dark with your eyes closed.
Pictured at left: Me and my lightsaber, using the Jedi Mind Trick of invisibility. I've turned off the lights so you can see the lightsaber better.