Some schools hold revisit or second-look visits for accepted applicants to come back for a weekend. It gives applicants a chance to evaluate the school more closely than during an interview (when we were too busy being evaluated ourselves), and also to meet with faculty and students. I'm looking forward to revisits as a chance to compare specific things about the schools I'm still considering.
The one thing I'm not sure about is how many schools hold revisit weekends. I know my cousin is going to Creighton next year, and she doesn't have a specific revisit weekend. She may just make a trip out there herself.