Mechanical Lego Computers?

Some enterprising soul has created mechanical Boolean logic devices using Lego. Hypothetically, you could create a simple computer using many thousands of these, although it would be incredibly slow, cost an outrageous amount of money, and take up an awful lot of space. Of course, the relative imprecision of Lego bricks also would render the whole thing completely useless since the gears would bind up on the first operation.

Now, I always say that the two best reasons for doing anything are "because I can" and "because you said I couldn't," so I'm going to say that it's impossible to build a working mechanical Lego computer and patiently wait for someone to do just that.