Purplehayes, we have the exact same compulsions.  THis is really weird, because a friend and I were talking about habits last night, and I hadn't even looked at this thread.
 I read everything.  Cereal boxes while eating, shampoo bottle while taking a shower, toilet paper wrapper while on the can.  I need to read to go to sleep.  I have subscriptions to a dozen or so magazines.  I have a huge amount of books/novels, and I will read everyone of them over and over again.  Half of them have been read several dozen times, and are starting to fall apart.  I've had to buy 
The Beach, the novel, 3 times (first one fell apart, second one got lost).  And that book was only written a few years ago.  When I was 13 I think I read Jurassic Park 30-something times.  I could probably still recite every word in that book.
I'm the same way with the drumming, too.  I have one of those MS keyboards with a plastic wrist wrest.  The wrist wrest makes the most satisfying *cli-tick* when you hit it with your fingernail.  I'll be sitting down at my computer writing a paper and listening to mp3's and just bust out in a wrist wrest jam session.  I do the same in my car.  The turn signal and wiper stalks are positioned at 10 & 2, making for perfect tapping.  I don't really tap on the steering wheel, because I always end up hitting the horn, then I 
really look like a jackass. 

  Now, when my roomate hears me tapping on my wrist wrest, he lends me his bongo.  Amazing how I'm a brilliant percussionist on the wrist wrest, but he hands me that bongo, and I rhythmless.  Oh well, at least I get plenty of practice! 
 
I also have the disgusting habit of chewing on the cuticle around my fingernail (the skin, not the fingernail itself).  It's pretty gross.