Pre-order BioShock Infinite on Steam to help unlock exclusive rewards and free copies of BioShock and X-Com: Enemy Unknown. In a Ninostarter-type drive, rewards are unlocked as the number of pre-orders goes up.

The first tier is a free copy of BioShock for everyone; next is a set of BioShock Infinite-themed hats, because it is a game on Steam. Finally, if pre-orders reach a high enough number, free copies of XCOM will be rewarded to everyone.

If enough people pre-order BioShock Infinite, a free copy of the original BioShock gets unlocked. If thats not enough, a series of exclusive BioShock Infinite-themed items in Team Fortress 2 will be unlocked if the number of pre-orders reaches the next level. Lastly, Steam will sweeten the pot by unlocking a free copy of X-Com: Enemy Unknown once pre-orders hit that magic number. Of course, this is in addition to the Industrial Revolution pack that you will receive immediate access to just for pre-ordering. But to unlock all these rewards, youll need to spread the word and work as a team the more people who pre-order, the more rewards gets unlocked.

Amazon offers $30 in “2K Games Credit” with pre-orders of the PC download. You could always fold up some dollar bills into a hat.

• Vox Diabolus: With this Vox Populi anarchist mask, you can terrify your enemies into thinking youre the Devil Himself, or worse, a protestor. Either way, theyre probably going to avoid you at the entrance to the supermarket when you try to get them to sign something.
• The Pounding Father: Heavy cannot tell lie. Heavy is first President of United States. Of crushing little baby men.
• Blind Justice- Want to command respect from people standing at an indeterminate distance from your immediate right? Bolt on a platinum Pinkerton badge and experience the thrill for yourself!
• The Sydney Straw Boat Throw this hat on the ground to express rage, or in the air to express joy! Take a hat-based trip through time to learn how your great grandparents displayed emotions in the days before emoticons!
• The Person in the Iron Mask- Turkey? Chicken? Game hens? Your head? This cast iron poultry furnace will smoke anything placed inside it.
• The Doe-Boy Protect the important thoughts in your head ones like liberty and freedom and democracy with good, honest, hat-shaped American steel. This helmet wont run (until heated to 2500F)!
• The Steel Songbird It gets pretty quiet in that snipers nest. Why not treat yourself to the haunting rhythmic symphony of bolts being constantly pooped by this mute, easily terrified incontinent bird?