On Bribing People to Become My Friend

I have a question for you guys.

Justin is leaving for Afghanistan in a few months and I'm faced with a quandary... How do I make new friends when he's away and when I work from home all day? 

Man, making friends used to be so easy! Back in the day, I'd chat with the girl sitting next to me at school and invite her to my house to play Legos. Voila, instant friend! But now that I'm 27 and have moved back to my hometown, I realize most of my high school friends have left for New York and my college pals live on the other side of the country. What's a girl like me to do?

I've been fortunate enough to have met some wonderful, wonderful people through blogging and various writerly forums. Thank you, Lynn, for our marathon lunch sessions! Thank you Jessica and Robin for our Gallery Place adventures! And thank you Alexa and Ellen for being so cool and not thinking I'm a crazy person! Yes, I count myself as very lucky to have met these great women.

But...my newfound friends have very busy lives to lead and I'm sure they don't want me calling every evening to ask, "What are you up to? Mind if I come on over? Aw, why not?!" Thus, the question remains: where do I find more people to add to my friend collection? At the mall? At the park? Just around the river bend? 

I've thought about getting more involved at my library, maybe join a book club if they have one. Or I could do some volunteer work. Or I could take a class while Justin's away (perhaps painting or web design). Or...something else! 

So how have you guys made friends since college? Any advice for me? :)