My roommate went home to see her mom for Christmas. She took her cat with her so that I wouldn't have to take care of her cat for her while she was gone. Not to say that I don't miss my roommate, but I miss her cat a lot too.
Recently, her cat started sleeping on my lap while I was on the computer. I even have scratches on my legs from when she suddenly decided to jump off on several occasions to prove it. There's just something so nice about having a cat happily on my lap while I do whatever I'm doing. In general, the cat would just come around periodically to see what I was up to and cause some trouble when she wanted attention. Sure, she was sometimes a little bit of a nuisance (like when I'm trying to fold my laundry but she wants to bury herself in my warm clothes), but at the end of the day, I really like having a cat around the house.
I'm going to be even more sad when my roommate finishes her degree and moves back home. I really want to adopt a cat of my own at some point now. I think I've proven that my allergy to cats has diminished enough that I can handle it. =)