Hmm interesting options!
I don't really like holding things when I run so I think it would have to be a belt thing or the camelbak type option. I feel the heat so I hate the idea of something covering my back but the belt thing would annoy me if it bounced.
How warm do you get in your intensity pack SK? Do you use the same sort of thing Yellow?
The most effective way to do it, is to do it.
Amelia Earhart
2005 Trek 5000 road/Avocet 02 40W
2006 Colnago C50 road/SSM Atola
2005 SC Juliana SL mtb/WTB Laser V