Instead of spending a ton of cash on those fancy rolling suitcases, why not build one yourself by adding detachable wheels to nearly any bag you already own. Instructables user RonnyK demonstrates this pretty simple process by adding two velcro straps to the bottom of a duffel bag and then strapping the wheels in. This way, you can easily remove them if you need to use the bag for something else.

Head over to Instructables for the full step-by-step directions.