Over the years I've been on a few sites and at first met a bunch of guys. Then I got much more selective.
Lately I've found that others were right about joining clubs and such. Growing up as a JW I picked up a distain for clubs and all sorts of extracurricular activities. It's taken me sooo long to get over that. I now belong to a riding club with about 30 members. Going to the gym - especially same day, same time each week - you will meet people.
Taking a class is another great idea. And this has the added benefit of furthering your education.
I'm cautious about Craigslist, but there is a section for Community (especially 'Groups' and 'Activities') that might help you find someone to hang out with. Even if it's just once or twice, it's a start. I've found a few people in the 'Strictly Platonic' section. I had an extra ticket to a sold-out show and placed an ad. I got over 15 responses, took one person and met about 5 of the others. Could have met more but got too busy!!
I think the key is to keep it simple. Be open minded. Don't get into heavy discussions until after you've know the person for a bit (maybe not even then!). Stay safe by sticking with public venues like coffee shops.
Have you tried organizing a little apostafest? They don't all have to be elaborate.
Let us know how things go. Good Luck and have fun!
-Aude.