I love the idea of cycling in regular clothes, as it would remind others that cycling is a practical means of getting about. As an ambassador of cycling, I sort of see it as my duty to cycle everywhere in my regular clothes as often as I can. But on the commute, I suffer with chafing, particularly with jeans. My commute is 10 miles and very hilly, as I like to go at a fair old pace to keep time spent travelling to and from work down but also get my exercise, I sweat a fair bit, so regular clothes just aren't practical. If I wasn't in a hurry, I'd be happy to wear normal clothing on the commute, but as others have said, jeans can be uncomfortable. I really like Levis commuter series though, technically not "normal" clothes, but they look it. Sadly, they are too hot in the summer, and not quick drying in the wet, so their use is limited to jaunts to the supermarket, social calls, the pub, fair weather rides etc. I picked up 3 pairs at some decent discount in the US discount stores, so tend to wear them as often as my regular jeans, even around the house.