Creighton med student here. Just wanted to congratulate those that received invites and encourage you to utilize the student host program. Class hasn't started yet so the program may not be "officially" set up, but if you e-mail admissions, I'm sure they can get in touch with the students in charge to accommodate you.
Briefly, it was $40 a night last year, which gets you a ride to/from the airport from your host, a place to stay for the night with said host, a ride to/from the interview and the chance to spend time with a current student so that you can ask questions and all that good stuff. It really doesn't make sense not to take advantage of the opportunity.
Also, if you can, definitely try and stay for the host dinner as it gives you an extra chance to see what the students are like, see the city of Omaha, and talk to current students in a very relaxed situation. Whether you go or not will not affect your chances, but it's just another chance to help you figure out if you'd like to spend 4 years (or 2 years if you do the newly created Phoenix track) of your life in the big O.
Good luck!