Backpacks are convenient for hauling stuff but can cause an uncomfortable amount of sweat when riding a bike. Messenger bags and panniers are both alternatives and you do not always have to purchase an option off of the shelf. Back in February of 2010 Devon sent us a great hack showing how a dog food bag can be turned into a messenger bag.
We received another great submission showing how to transform an Army duffel bag into a messenger bag/pannier fitted for a laptop. Visit Ron's Workshop to see how you can go from this . . .
. . . to this in six easy steps.
Pictures Credited to Ron's Workshop