Hello from Louisville. I'm in my upper 30's, and BRAND new to biking (but for my old college comuter hybrid I've been riding my children around the neighborhood on for the past 6 years). Just recently (late October) I was introduced to cyclocross by a friend who is also a serious road rider and got immediately hooked. I just raced my first race (one week after seeing the sport for the first time, and never having ridden any sort of road or mtb, especially in a race setting). I had to borrow my friends mtb for the race, and buy SPD clip shoes (also a scary transition from tennis shoes and regular pedals) b/c I'm still figuring out what I need to get. The race went great, though, and I finished in the middle of the field in a Cat. 4 race. I am a runner, and I'm hooked on this as a way to get dirty, have some fun, and keep in shape. I anticipate that I might also make the jump to duathlons as well, once I get comfortable on the bike. Right now I run a fair number of local races (not to win, I'm about an 8 minute per mile runner), and am going to try to get as much cross in as possible this season.
I actually lucked out in that I have the opportunity to get what I think is a pretty good bike VERY cheap from a relative (with more $ than me), who bought it, rode it twice, and doesn't want it. It's a TREK 7.5 FX, so it needs some modification for cross (drops, cx tires, and new shifters is really it, I'm hoping), but could also be quickly switched for duathlon road riding when needed, I think.
Anyway. So far, so good. I'm looking forward to "lurking" in the forum, since I can't imagine I've got too much insight into the sport yet, but I'll probably have some questions, and maybe a fresh perspective on cross and biking in general.