I'm currently reading the Athlete Guide for the Pocono Mountain 1/2IM. Rule one of the run is "no form of locomotion other than running, walking, or crawling."
I hear there's a video out there of a pro crawling across the finish line of a full IM.
I'm also a little peeved that they've changed the wave starts and I'm now starting a half hour later than I expected. I will therefore only have a 1.25 hour buffer. I don't feel comfortable with that short time. Especially, since I haven't figured in transition times!