I downloaded "Crossover Games", a program that lets some games run on mac. Of course, I torrented this instead of buying it. I also torrented a copy of TF2. Although I've had a few problems a few times, I've gotten as far to run the game properly, and open up the "find servers" menu, and actually see servers. If I try to join one though, I get the error "Invalid steam key ID" or something. It wasn't ike I wasn't expecting problems, but does anyone have any suggestions?

Buy the game.

The least you can do is buy the seam key ID.

Get Steam and buy the game. Most likely you'll need to get Windows as well, cause as far as I know, Steam doesn't work on Mac. And how dare you torrent an awesome game like TF2? ;P

It was more of a test then anything. I wanted to see if this 3rd party thing worked, and I didn't want to buy a windows game, open it up, and it be completely useless.
I might buy the orange box now, knowing that it works.

It actually says "invalid steam key id size", my mistake.

You'd probably have an easier time with a singleplayer game like Half-life 2 instead. Call of Duty 4 is one thing, but Steam as a platform is another. I'm sure it's been cracked, but I'm also sure it's a lot harder.

Of course, the last game I torrented was Baldur's Gate when I lost the CDs.