For those who want the fun of a live animal without the actual "omg I take so much effort," I recommend Sea Monkeys! Yesh, they do sound lame, but they're really easy to take care of. You feed them, change their water sometimes, and become aghast when they mate, because it looks like they're dying.
http://www.discoverthis.com/seamonkeys.html
I've raised Sea Monkeys before, but they die relatively fast for me, even though I did it in high school. Because you'll probably have a bajillion books, the towers are sort of... spill-attractant. So I recommend their newest set, which I will buy for this semester of college for zenniness:
http://www.discoverthis.com/sea-monkey-city.html
It's flat with a top, and if you have to move them home, just do a quick duct tape job with a little of the lid askew or wedged to give them air and prevent spillage.
Or, if you want something bigger that requires a bit more maintenance, lives shorter, but are actually quite fun:
http://www.discoverthis.com/triops.html
Triops, mine grew to about 1.5 inches long. I have had the DLX kit, so it was easy to tote around, but the cleaning is VERY tedious. You have to clean their water once a week by transfering them out into a bowl, emptying a lot of the tank water, and refilling it with BOTTLED water. Mine lived for 2 months. Fed about once or twice a day after they mature. THESE THINGS ARE BLOODY CANNIBALS T_T they ate one of my smaller ones