I carry a .38 J-frame almost daily, depending upon the situation. Usually in a pants pocket holster or in my jacket pocket.
When I worked in Atlanta, I always carried when I went out on homcide calls. Usually it was a Titanium Taurus .38.
I never travel the highways without a gun in the car. Sometimes its a .38 K frame, but I have carried .357 K-frames and a Ruger Blackhawk .357 as my car guns, too. I also had a Makarov as a car gun for awhile.
My first car gun was a .32 S&W J-frame w/3" barrel. Not much, but it was all I had at the time. It was very accurate even if it was weak. I actually thwarted my own car-jacking with that gun. They didn't expect me to pull out a gun and point it in their face. But when it came out, they knew I would use it. (I drove home just fine). I also carried that gun a few times when I was in bad parts of town.
I'm picking up a Ruger Redhawk later this week. In addition to hunting duty, it will be my car gun, too (stoked w/.44 specials for social work).
-David