Great bookcase design, Mr. X! I'd buy one as soon as I reinforce the floor of my mobile with super-stregnts cement pillars, and steel plates!
Oh, And I'd also have to raise the ceiling a little bit.

The only problem is that if I don't see what books I have, I'll forget that I had them! But at least, the machine would know where they are.

Any chance of getting my hamster's wheel hooked up to the bookcase to recharge the 27 AA Batteries? Now, that would be one GREAT playground for the cats, if they ever can find their way out again and avoid all the internal gears!

There is an optional hamster power kit available.

It requires one healthy hamster and will recharge the 27 batteries in about 42 hours of wheel running. Or just use the included AC power pack.