My commute is about 5 miles (a little shorter than that right since a handy construction detour cuts out some backtracking), and it's straight down a fairly busy street in Salt Lake City. (2100 South for those familiar with SLC). There's about 800 stop lights between my house and my office, and they're always red. Even with all of the red light waiting I can make to the office in about 20 minutes. It's about 25 minutes to go home though since I have go up all of the fun morning downhills, and fight with more traffic.
I commute in my regular clothes, but I've been thinking about picking up some decent bike shorts to wear under my clothes to keep my boys out of the way. The nylon briefs sound like a good idea, too. I've had those in the past for running, but ran my way right through them.
Some days I ride to downtown SLC for lunch, which is about 12 miles R/T on a MUP from here. I can make that in about 20 minutes, which gives me just enough time to fool around in a bike shop or eat something off a street vendor cart. It's really more about riding my bike than eating lunch though.