Well, not for a BOB - but I've built a couple of pulks using plastic toboggans, PVC pipe, etc. I used duffel bags to hold the gear in them and lashed the duffels on with cord.

They've worked great for hauling in heavy tents, double sleeping bags, yummy food, and other winter camping treats. I've used it with both snowshoes and skis, and it's been fine for both. Last time was a few months ago for a spring haul part way up Lassen Peak in Northern California.

Anyway, I think they're great, and they're easy and cheap to make (though there are several commercial options out there if you'd rather spend the $$).

- Steve