Amanita Design has started taking pre-orders for their upcoming 2D adventure game Machinarium, and customers who purchase it early will get a three dollar discount off the regular price of $20. Buying the game before it is launched also entitles you to a pre-order pack that comes with songs from the Machinarium soundtrack, among other things.

Machinarium is scheduled for a release this October 2009, and will be available for both Windows and Mac OS X operating systems. (source)

Amanita Design blog