I am members of a geocaching site, 4WD forums and a couple of online games, I find these things browsing mainly overseas forums if I like it or think someone else might like it I save them to my photobucket album.
Its pretty cool its like a worldwide treasure hunt, http://www.geocaching.com will get all the answers you need I have done about 10 now good fun on a Sunday when its too hot to do anything else, just jump in the car crank the aircon and off you go.
At the top of the page you'll see a 'Profile' menu ... click on that and you'll find out the info you need about yourself. Down the bottom is all the avatar stuff. The only thing is you'll need to have your avatar hosted from a different site such as photobucket.