Confession time. For over a year now, I've been playing with Lego. At first, I was a little hesitant to mention it to anyone. After all, I'm an adult playing with a child's toy, right? That's pretty... um... odd. To say the least.

Since then, I've encountered many more adults with the same odd obsession. As it turns out, it's entirely likely that this Lego kit is enjoyed by more adults than children.

The Lego kit in question is the Mindstorms Robotics Invention System: a programmable microcomputer that lets you build and program your own robots. Actual, real, autonomous robots. Introduced in '98, the kit became an instant sensation -- a fad that sucked in countless people into the depths of geekness and spawned hundreds of Mindstorms fan sites.

So, yes. I have an odd hobby. Visitors to my home often have to avoid treading on some little mechanical creature or other robotic gadget. They may well think that I'm completely insane, but so far they have been kind enough not to say so in my presence.

I assure you, however, that I am by far not the worst of the Mindstorms geeks. From the creations on display at JP Brown's website, it's obvious that I'm not even in the same league as the real fanatics. Did you know, for example, that a Lego robot could solve a Rubik's cube? And someone else hacked the firmware to create the first TCP/IP-enabled Lego brick.

My own attempts to build autonomous robots, then, are quite feeble by comparison. Oddly enough, that makes me feel better. It means that I am odd... just not as odd as those other guys.

I'm making converts, too. Recently, I lent one of my kits (yes, I bought two of them) to a friend. Yet another perfectly normal adult has been dragged into the zone of pure geekdom. Consequently, I may not hear from him again for months.