You can try finding a mall with a playplace or, if you're willing, go to a fast food place that has one (if they require you to buy something, just buy something from the dollar menu). My son is 18mo, and while the signs say they need to be 3, nobody has said anything so far and he seems fine just standing outside of the tubes and watching the other kids running around. I try and make sure that I go at times when there are other people, and then I make a "friend" with a parent with older kids there so that I can ask their older kid to fetch my son if he gets scared and lost in the tubes. So far, these trips have been successful.
Now, the mall playplace, the one near our house is great. The only problem is the open entrance. It's a circle of seats surrounding the play area, which blocks it off everywhere except the entrance, and my son started taking off out the entrance. I had to use some discipline and other tactics to teach him it wasn't allowed, and once he figuerd it out, we were fine...but this one might be harder for your handicap if it's not closed off.
Mom's group! Check Craigslist and Yahoo Groups to see if there's a mom's group in your area; some groups will post their information on the bulletin boards at churches, coffee shops, and libraries too. We meet once a week for play groups, and sometimes a 2nd or 3rd time during the week for other group activities that people think of. During the winter, our group meets at people's houses, during the summer, we meet at parks. It gives the kids an opportunity to burn some energy and learn to socialize.
Check your local webpages (if your city or county has one). Most towns/cities that are big enough will post information on their websites about what's going on in the neighborhood. They can give you some great ideas on what's going on and what you may be interested in taking your toddler to.