Except for charity and other organized rides, I ride alone all the time. Like caligurl, it's mostly because I live in a town with no LBC and very few cyclists. I think I can count on one hand the number of other cyclists I've seen around this summer, and I've been riding a lot. Plus, my schedule is crazy, so even if I did know other cyclists in town I may have trouble meeting up for a ride.

I do think that riding with a group would be helpful, though. I have very little skill with things like drafting and pacelines, and tend to weave all over the road. I also don't push myself as much as I could, mainly just tootling along.