www.meetup.com

You can start up your own, and they will show you how many ppl in your own area or surrounding area are also interested in that activity as well. There is a fee to starting up a group and keeping it up, BUT there is NO FEE to JOIN a group. Some groups ask for a monthly allowance of $2 or more, that's if you even attend for that month. You can make a free profile, simple and easy. Some are totally FREE.

I've Joined;

-a Chihuahua group
-a Photography group
-a Art Group
-a Do Something New group
-a Easy Hiking group
-a Entreprenuer group
-a Snow Shoe & Harder Hiking group

I have seen:

Vegan Groups
Potluck Groups
Scrapbooking Groups
New To Town Groups
Women's Groups
Toy Dog Breed Groups
Bunny Groups
Single's Groups
Single Mother Groups
Tennis Groups
Depression Groups
BPD Groups
Anxiety Groups

and the list goes on.....