i have a macbook and i want to get one of those numerical pads because i like typing numbers using that.. still have to get it though.
hooked up my microsoft mouse, mac compatible, with the buttons... love it on mac more than pc. the foolish magnifying button can actually be put to use on my mac (i use it to launch dashboard), the wheel button i use to launch exposé, and if i really wanted to, i can hold control and scroll the wheel to magnify. i don't think i'd like my macbook so much if i didn't have this mouse.
also got a Y-cable to hook it up to my big beefy stereo system.
edit:
i use one of those foamy zipper sleeves.. fits only the macbook, then i carry it around in my backpack. i also had an older small computer bag lying around, so i keep whatever i don't need right away in that. the zipper sleeve thing is the best though.