"No rollerblades in store". But what if you could quickly slip a walking pad onto the wheels of your rollerblades, and negotiate any store, stairs, gravel, etc. Borrowing the design from the skate guards used forever on ice skates, this could save the need for slinging shoes over your shoulder, not to mention a lot of time. The design of "Wheelwalkers" would have to have an angled base so that you could still manage the walking motion in the boot shell of the blades.
Reward: I need new rollerblades (size 14 wide), and wheelwalkers to go with them.