I like the idea of the simple commute. I think this is one of the main attractions of biking for transportation. You can accessorize all you want, but it's easy to ride simply too.

I have a 6.5 mile moderately hilly suburban commute. I wear whatever I'm working in for the day, typically business casual (khakis and button down shirt, sometimes with a tie if I have meetings, jeans/t-shirt on Fridays). I wear normal leather dress shoes and use standard platform pedals. I own very little bike-specific clothing beyond helmet, gloves, rain pants and a light outer shell jacket.

My bike has full fenders and a rear rack. A trunk bag carries all my bike tools, spare parts and rain gear. My work "briefcase" is a backpack, in which I carry papers, laptop, food, meds, etc. My bike does have lots of lighting. I don't skimp on good lighting because I ride in traffic and in the dark sometimes.

I have to agree with other posters about having a small fan at work. I come in and sit in front of the fan for a few minutes to blow off the sweat. Also have one of those little fold up hairbrushes to brush out the helmet hair.

I know some of you feel strongly about this issue, but I'll mention it because it's relevant. My bike is electric, so I don't HAVE to pedal too hard and can limit my sweating. That said, I always plan to "take it easy" on the way in and arrive way sweatier than planned. It just doesn't feel right to not pedal as much as I can, although I love the motor for the hills and those nasty headwind days!