Any cat owner will tell you: those felines love keyboards. They love sitting on them. They love walking on them. They adore them!
Over on Yahoo! Answers, the top answers state the obvious: cats want your attention. That's no doubt true.
Recently, Japanese site My Navi examined this issue that has confronted cat owners as long as there's been computer keyboards. Cats, My Navi pointed out, love warm places, and computers offer just that. In fact, cats like temperatures as hot as 126 degrees fahrenheit! This is why cats are always lounging in the sun, and this might be due to the animals' desert ancestors.
What's more, cats love things that move and make noises. Computers are a hive of activity, with things happening onscreen as well as blinking LED lights on monitors, computers, and keyboards. The cursor, in particular, is of great interest to our feline friends, My Navi notes. Its movement probably reminds cats of insects.
Keyboards are somewhat pliant in that they "give" when they cats walk across the keys, pressing them down. Cats love soft things, and this probably also helps keyboard seem like a cool kitten place to hang out and punch out a few paw strokes.
There's even a slightly humorous Wiki on how to get your cat to stop walking on your keyboard. One of the things it recommends is not showing your cat things on the computer.
My Navi mentions the U-Board as a possible compromise for cats and their owners. The U-Board was originally designed as a shelf to help organize your desk. It can also double as a space for cats to sprawl out and leave you to your typing. (You know, instead of this.) Though, you still can't see your keyboard, which might be a pain...
Cats want attention. They want your attention! And if you are spending too much time at the computer, a stroll across your keyboard is your cat's way to say, hey, look at me. But since the area is warm, active, and tactile, it makes the computer a place your feline friend likes just as much as you do.
猫がPCのキーボードに乗りたがる理由 [My Navi]