I personally don't like to carry a bag slung over a shoulder- it makes my back sweaty and I feel unbalanced. But they can be a dramatic statement
Big graphic colorblocks with a star (note if you can the streetsign- very MIT)
Skinny jeans, enormous bag
The Scientist has been riding to work this week for fun, and he's been in a quandry about how to carry things, not having a rack on his road bike. He's been borrowing my Freitag messenger bag, but I don't think I could do that every day for very long.