normally just use the trackpad, muti-touch kicks ass!! But for gaming I use the a logitech MX1100, it takes up a usb port, but it's big for my "Goofy" ass hands.
I got a Logitech Air Mouse back in December. It is the most unusual mouse that I have ever owned. I does take a bit of getting use to moving the mouse in thin air....it is great. I have several cats and they park themselves on my computer desk. They know when I use to use a conventional mouse that I'm not paying attention to them and they would park themselves on my mouse pad. NOT ANY MORE, I JUST HOLD IT IN THE AIR AND CONTINUE ON WITH MY BUSINESS. It is the most amazing mouse I've ever owned. Cudos to Logitech.
at the moment i'm using a microsoft mouse on my computer i've used the might mouses on mac at school before it horrible i feel like i can crush the mouse in my hand :S
Right now I'm using a touchpad on my laptop. I don't actually have a mouse for it, but I though about buying an Arc Mouse but looked online and it sounded like people were having problems with the scroll wheel breaking after 2 weeks or so, so instead I got GTA IV and a DVD. I have a 3 buttons scroll ball mouse on the desktop which sucks, but whatever, it's not terrible and I don't use it as much as the laptop.