Aquariums. I've been thinking about getting an aquarium, because I don't have enough money to afford any other kind of pet, let alone pet deposit. Some of the aquariums on the net are pretty interesting. Way, way, way out of my budget, though. Custom aquariums, even - yeesh! Information about aquariums and home water-based stuff like that is as extensive as the number of aquarium dealers on the web. Pretty interesting, I suppose. I never really think about it, except when I'm somewhere that has them, and then I stare at the fish for a long time in a kind of dazed state.

Here's an interesting quote:
"You see, wire telegraph is a kind of a very, very long cat. You pull his tail
in New York and his head is meowing in Los Angeles. Do you understand this?
And radio operates exactly the same way: you send signals here, they receive
them there. The only difference is that there is no cat."
-- Albert Einstein, when asked to describe radio