This is a blog that I have in my Google Reader, "Paleo-Zone".
This guy, Steve, does Crossfit, and eats Paleo. Paleo Good. Crossfit Good. Moog like lift heavy sticks off ground. It make Moog hungry. Moog need food.
Check this out: http://stevepaleo.blogspot.com/2009/09/introducing-bison-paleopak.html
The reason I like Steve's idea here is that it is convenient. I would probably go so far as to keep one in my purse or work bag. And they would definitely work for a day hike / ski trip nibble to keep you going.
I might actually cut it up into smaller portions - 1 or 2 blocks to use as a snack.
And if you can't find bison, a good quality local beef jerky works, in my opinion.