My warm weather commuting garb consists of a pair of brushed nylon climbing shorts that have no seams in the critical areas, an inexpensive running t-shirt, and Shimano sandals. If it cools off enough here in Texas then I break out more cycling specific gear. Cycling pants (not tights, but snug), cycling vest and a long sleeved running shirt. I own lycra, but I prefer the other for my commute. After all the sandals look a bit funny with the tight shorts and jerseys.