What are the best ways to meet new people?

I am going through a breakup I believe. It’s not yet confirmed but all signs are pointing to a split. Wise old saying “Nothing gets you over the last one like the next”.

I’ve joined several interesting groups from skydivers to cooking to photography groups on meetup.com.

I’m just wondering what other sites or venues (besides clubs, bars) can I use to find interesting groups of people.

P.S. Fluther folk are awesome!