I couldn't decide whether to put this here or in the commuting forum.

I'm looking at commuting to school and doing some errands by bike for grad school. (Dependent on where I'm living, of course. If it's walkable, that's even better!) I've decided against using my road bike for commuting. It looks more expensive than it is. It's also a little less practical--it'll take a rack, but not fenders, and I wonder how well it'll handle with a week's worth of groceries. (Maybe I'm being paranoid here and it'll be fine, but there's still the "STEAL ME!" factor!)

So, what do you look for when picking a commuter? Obviously the ability to take fenders and a rack is important because I don't like riding with a backpack or getting wet and muddy.
What should I generally be looking for? Other than for something used, of course!