Not 100% free - costs 82 cents (2 US mail stamps) for a free sample of dirt that may have some gold in it. I saw the link on a metal detecting forum and some found tiny (pin head size) gold in the sample. Supposed to take about 1 week to arrive. I guess if you have kids it may be fun?

Heck with the kids, I'll order some for myself LOL

http://www.felixpaydirt.com/form.html