mtnbud, If you're thinking you'd like to have the backpack with you for hiking, the Burley Travoy seems like it'd make the most sense. The Travoy would be ideal for situations where you want to ride your bike to a hiking trailhead lock up the bike out of sight and then go backpacking.
That's exactly what I'm thinking. Thanks for the links, I like the homemade Travoy. I was considering doing some thing like that.