In my day-to-day life, I rarely come across women approximately in my age range (20-24), at least not unaccompanied by a boyfriend/significant other. I'm one of the youngest people at my work because I've recently graduated from college (yeah, there were a lot of women there), so there really aren't any women in my age range there, let alone ones who are single (people getting married is endemic in a corporate workplace). I work out at a gym near where I live, but it's mostly guys there, and a lot of the females there are middle aged or appear to be still in high school.
Most of the contact I have with women roughly my age is when I go to a restaurant or a gas station; sometimes the cashier or waitress is a woman approximately my age. Actually, last week a cashier appeared to be flirting with me, so I asked her out, and she then said she had a boyfriend.
I don't drink alcohol and am pretty uncoordinated (in terms of fine motor coordination at least), so bars and nightclubs aren't most suitable for me; I actually tried going to a nearby bar last weekend simply out of a desire to meet some actual women, but it was at least 2/3 guys. I am nonreligious, so I definitely do not want to meet any women through a church or youth group. Offline I have no friends, so I can't network to meet women.
Mostly I have been sending women messages on MySpace and Facebook, but over the past two years, that has resulted in the occasional exchange of messages but no on-going friendships, no dates, and not even meeting any of these women in person.