The volume of people to whom I tend to be attracted to would make this pretty infeasible.
Well, outside of contexts where people are expected to be hitting on each other (dance clubs, parties, speed dating events, OKCupid, etc.) it's hard to advertise yourself to strangers without in being socially inappropriate. On the other hand, within an already defined social circle that's been operating a while, people do tend to find out who is single and who isn't.
I guess you could try a T-shirt?
r/Fitness does a weekly "Moronic Monday", a judgment-free thread where people can ask questions that they would ordinarily feel embarrassed for not knowing the answer to. I thought this seemed like a useful thing to have here - after all, the concepts discussed on LessWrong are probably at least a little harder to grasp than those of weightlifting. Plus, I have a few stupid questions of my own, so it doesn't seem unreasonable that other people might as well.