I'll second this. I lived in State College for a while and Meyer's has good ice cream as well.

If you're staying for dinner you and the family could walk around downtown State College. It's two streets, Beaver and College and there are good local restaurants.

I don't know how up your family is on Penn State but it could be fun for the kids to take their picture with the Nittany Lion.

I'm not up on science on campus but I bet if you called a science department (physics, chemistry, biology, etc.) early enough ahead you could get a tour of some stuff. Check each department's website and see if there are any cool projects going on. Grad students would love to have someone to show off their research to.