I just had to pass on the link to this cute organization I saw at the Craigslist Foundation Boot Camp a couple weeks ago, Realidate. I'm an old married lady now, but if I was out in the big bad dating world, I'd be signing up with a service like this. Basically, folks sign up to do service projects (like sort food at the Food Bank), or to attend nonprofit fundraisers (like a wine tasting to benefit a Boys and Girls Club), and have an opportunity to meet other realidaters looking to, "Find love . . . while making a difference."
From my work with volunteer groups like One Brick and Hands On Bay Area, it is pretty clear that some flirting and socializing is happening during the group's project, but I like that Realidate puts it right out there, it is ok to do good and have a good time!