Mirrors On The Moon
This can be done by just about anyone. Ok, maybe not everyone, but plenty have done it and it proves men have been up there.
Basically all you do is buy a laser and a detector and a light collecting mirror. Then you fire it at a precise point on the moon. There is a reflecting prism there that acts like a mirror, placed by Apollo astronauts. Now if there was nothing at that point but rock that would be the last you would see of your laser. But time and time again scientist have been getting their laser reflected back. Indeed, they have done a number of experiments using these reflectors. This experiment has provided a very accurate method of measuring the distance to the moon. Due to these measurements we can now tell that the moon is actually steadily receding from the Earth.
http://www.redzero.demon.co.uk/moonhoax/Mirrors.htm
Yup, they left mirrors up there, and they're watching you, don't forget to wear your tinfoil hat.