Back at Ohio U, I used to skate all the time. Never for transportation reasons, though. We just used to like going out and hitting the curbs and handrails around campus. We would put in about 5 to 7 miles just rolling from one spot to the next, over blacktop, concrete, streets, sidewalks, even a few sections of bricks and stairs.
You can use skates as transportation, but you have to figure on carrying shoes for when you get where you're going. Either that or a set of wheel guards you can clomp around in when you have to go inside. The other things to figure is that the hard durometer of the wheels makes them very prone to slipping when it's wet out. It really sucks to skate in the rain.