I commute with my mountain bike. I did switch out the really nubby tires for more sedate nubbies, but not slicks. I no longer enjoyed trail riding after I took a terrific spill in Park City, UT. I have a trek 6500. I have a rear rack and a set of panniers where normally, I only have to use one at any time. I have a blinky light off my pannier. I carry a camelback with a little bit of water and have another white blinky light hanging off it. I also have a halogen headlight, since I commute at 4:30 am. I take a trip up to work by car on the weekend and take my clothes and lunch for the week. My bike ride in the morning gives me the energy to make it through the rest of the day....Enjoy your commute. Mine is only 5 miles (uphill), but it really aids in my outlook for the day.