I agree with Mutagene! I can't even LEAVE this town! Buses don't run through here, and taxis are way too expensive to be worth a damn! Without a car or a license, you're pretty much screwed! Not to mention that car payments, maintenance (oil, checkups, etc.), insurance, gas, etc. is all TOO expensive (in total) to even be considered by those of us who don't have a good enough education, those of us who don't get enough hours at work, those of us who don't make more than $5.50-$7.00/hr (depending on where you live, that's all minimum wage), and those of us who either don't or can't hold a steady job!
I don't really see Last.fm as social networking, to be honest. I used to (don't really now) just use it to keep track of my music listening habits purely for my own use. Same reason I use backloggery in my sig.
My coworkers dragged me kicking and screaming to facebook. I don't really make much use of the thing beyond to post inane commentary at specific people.
Last.fm I mainly use when I'm in the mood for some music other than the boundless assortment on my hard drive. It's good for occasionally discovering new music that you're about 80% guaranteed to like.