Haven't checked in here lately - nice to see there's still some interest!
My main commuter bike is a cyclocross-style Habanero titanium frame, with Mavic Open-Pro wheels and an Ultegra triple drivetrain. It's light and bullet-proof. I've had it for several years and have put a zillion miles on it. Cyclocross bikes allow the use of fatter tires than road bikes - I run C700 x 35 randonneur (almost slicks) tires, which make for a cushy ride and will go off-pavement when required. The bike is fitted with a Topeak rear rack, and I have a couple of their bags in different sizes that click into it. I have modified the trunk part of these bags with foam to carry cameras.
I also have a beautiful Rivendell Rambouillet steel-frame road bike that I use for longer-distance riding, but it seems, more and more, that I am riding the cyclocross bike almost exclusively - it is a very versatile bike.
I hardly ever use the car in the summer, these days. Cycling, for me, really changed my life from a health point of view. I lost 70 pounds over a couple of years. As I got more fit, my riding style evolved from riding a comfort bike to a hybrid bike to a road bike and finally the semi-custom cyclocross bike, over a span of eight years or so. I've spent a few bucks along the way but don't regret it a bit - look what a gym membership would cost, plus gas and upkeep on the car.
Keep riding!
Mike