If you live in an urban area perhaps you could try using something like craigslist. Sometimes when I have somewhere I'd like to go or something I'd like to do, I'll put up a post stating just that. "I'm going to a baseball game." "I like art museums." "I enjoy tennis." Sometimes I get replies sometimes I don't. Most often messages don't go longer than an email or two, but other times they do. I've met people with common interests before doing this. You said earlier that you're looking for something deeper than just a casual friendship, but hey, you've got to start somewhere.