Expanding on Squirmy, because I love Pony Meets!
If you live near Minnesota, we are pretty active! The pony fairs forum seems to focus more on the big fairs, sometimes the smaller state/region ones don't make it on there.
If you are hoping to find someone near you, you should put your state/region into the topic line.
Many years ago, I went to the Wisconsin Meet, and it was amazing... I wanted more! So I put up a post here, planned a day, borrowed a small local building, and invited all my pony pals. Since then, our group has tripled, I have new friends, and hilarity has ensued. We have it at people's houses now, and I know I look forward to them for months.
You don't have to be that elaborate, either. You can see if anyone is in your area (ask on the arena!) Who wants to meet for coffee or at a local toy store.
You will probably have to drive a little ways- I crossed Wisconsin once, so two hours to the big city isn't bad at all!
Be careful, though. These things are addicting!