I am 29 and live in Springfield, Illinois and have been living here for about 3.5 months now after having moved from the St. Louis, MO area. I pride myself on being as active in the Church and my community as my schedule allows. I was able to do a lot of good work in St. Louis (ie St. Vincent de Paul Society, etc) but it didn't lead to any social enhancement. Springfield has been better in the social sense but not as good as far as service and faith enrichment goes (thus far).
The Diocese of Springfield has a terrific program called YAM (Young Adult Mass) that is primarily for 20's-30's Catholics and it has been my lifeline for meeting peers and partaking in things I like to do as a Catholic. Check out their website: springfieldyam.com/
We usually have a service project and at least one social event every month as well as 8pm Mass every Sunday at our Pastoral Center. I'm working hard to get more people involved and to garner more interest in different activities. YAM does Theology on Tap every month as well, it usually draws a nice sized crowd.