At a place I used to train at there was a vaulting group (mostly kids) that ran out of the barn.
One day they got a pack horse to try out as a vaulter. They didn't want to be putting their kids (all under 12) on the horse to see how broke it was, and at 16 I was 90lbs soaking wet... So I got to test ride it to see if it was broke (it didn't buck, but it also had no idea what turning or going from the leg was... haha) and then hop on him in vaulting gear =) It was super fun and once he learned the voice commands on the lunge he was awesome!! Totally used to having things all over his body from packing and because he was never broke to rider's aids, never tried to do anything like go faster, or turn from what the vaulters were doing.
It's tons of fun - I wish I had gotten into as a kid, but now I would probably kill myself hahaha.
Looks like you had a blast, Allison!!
They say money doesn't buy happiness -- well happiness doesn't buy horses!