Great thread!
I ride 7.5 miles right now. In July when I move, it'll be 5 miles.
I commute in my regular street clothes with a spare shirt to change into. I ride on a Specialized Sirrus with fenders soon to have rear rack. I just carry my gear in my back pack.
Going to work, its all downhill. Going home, its all uphill. When I move, it'll be mostly flat.
Just a nice simple commute.