I recently got a job that is within biking distance, and when things fall into a routine, i will start to bike to work.

My question is, I am looking at giving a bag a shot, but not sure where to start. The bag will be mainly used for my change of clothes and items to clean myself with after the ride. I would also use it for running to stores. I thought about a rack and pannier "sp?" bag set, but i dont know how much use I would get out of it. Most of the places that I would like to go are within biking distance.

I am looking at a traditional backpack, messenger bag or a sling bag.

Any thoughts, or personal experiences?