I roller blade! I have a pair of old Roller blade Spirit Blades. They are in fine working order and they have the advanced braking system, which is a more intuitive way to stop (you just lower your calf down instead of lifting up with your toes).
My wheels are not so free that I can go super fast, but maybe I'm safer that way, and have to work harder, I don't know. My regular route is about an hour and fifteen minutes round trip. I think it's 9 miles but I'm not sure. I go from Walnut Creek through Alamo to Danville and back (this is in Northern Cal on the Ironhorse Trail). It's a great paved trail that's pretty flat and crosses streets infrequently, so you can get going quite fast between intersections.