Ideas for 'Most Gullible?'?

I'm going to take picture of high school seniors for Senior Most such as (most likely to succeed, best dressed, best smile etc.) I wanted to know if anyone had an idea of something funny and/or creative to have the guy and girl pair do for the 'most gullible' picture. One year they had them staring all schocked at a sign that said "Summer Cancelled", I have some ideas but just want to see if I can get any better ones.Thanks!