Psychonauts, then today is your day: Double Fine has announced the game is available for Mac OSX. The Mac port is currently available on the Mac App store and Steam, along with other digital distribution channels. Accompanying it is a free iOS app that allows you to view all of the game's Memory Vaults right on your iDevice, along with new commentary from Tim Schafer and Scott Campbell.
The PC version of the game has also been updated to allow for achievements and cloud saves on Steam, plus it scales down the difficulty of the Meat Circus. Additionally, we'd like you to do a us a favor and not google "meat circus."