Well, I personally LOVE Body Glide.
And, you can get it in a travel size that fits great in a jersey pocket.
When I did the MS150, I reapplied this at every rest stop to my bottom... and I didn't have ANY issues.
I have tried the Chamios Butter (? spelling), and it just isn't all that impressive. I am running to the store to get more Body Glide today.
"Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather, to skid in broadside thoroughly used-up, totally worn out, and loudly proclaiming: WOW WHAT A RIDE!!!!"