Okay, so here are the medals (most of them, anyway) and how to get 'um:

Ultimate Spitter:
In the Saloon, click on the spitoon in the back, beside the barkeep's counter thing. Cuboy will then spit. Keep clicking on the spitoon until you get the medal.

Ultimate Pest:
Click on the box of tricks. At the bottom-right of the screen is your boss. Keep clicking on him until you get the medal.

Nude Boy:
Get five (5) beers to the drunk after learning the directions to the indian camp. After you give him beer number 5, he'll give you the naked (sorta) outfit. And walk around with it. I played the entire game wearing it.

Playboy:
Find the piano dude's sheet music in the desert (it's in one of the tumble weeds) and give it to him.
When he starts playing, you can jump onto the piano and into a secret area with a bar lady. Then you get the medal.

Ultimate Savior:
Bully the totem bullies and save the bear.

Ultimate Bully:
Help the totem bullies bully the bear.

Nature Boy:
In the desert, walk around (meaning anywhere on the desert, not just one place) and click on all the cacti you see, one of them should be a talking cactus. He'll give you his skin and you get the medal.

Do Lose Your Head:
Click on Cuboy again and again until his head comes off

Ultimate Winner:
Ummmm......Win?

Easter Egg: In the main menu, click on the Get a Cuboy T-Shirt Thing or whatever it says (you don't actually have to buy one), start the game and Cuboy has a Cuboy Shirt in his bag of tricks!