Cogitate - Manipulate LEGO TECHNIC gears, beams, conveyor belts and motors to complete the ten pre-built puzzles or create your own levels. [In my case - Then watch them crash in a heap when you test them.]
An' all the hot cats on the block have been doing it too - c'mon now, honey, I wanna do it with you. Anyone hoping to build their own Death Probe without dismantling the vaccum cleaner or floor waxer can rejoice. The creators of Roomba and Scooba have released a barebones version. Add-on software from Microsoft is available, should more ambitious types decide to pair iRobot's tech with LEGO MindStorms pieces.
First came the O'Reilly hacks series. There there was Make magazine, which claims to be the first magazine devoted to digital projects, hardware hacks, and DIY inspiration. Now a niche publication for Lego geeks who want to know everything about wee plastic bricks.
LEGO Logic Gates - It's like Babbage, but with bricks. All the gates except XOR are here, and he goes on to develop a clocked flip-flop. While practical mechanical computers may be out, even at the nanotechnological scale, nanomechanical memory may be in.