I recently discovered work by Joon Youn Paek who has some terrific explorations that challenge the use of everyday products by augmenting their original functionality. Pillowig, makes a humorous statement on our rapidly growing sleep-deprived lives by offering a functional pillow that you can wear as a hat. And Polite Umbrella adds charm by allowing you to shrink one side of an umbrella or the entire thing when passing by someone (I laughed out loud when I watched the demo of it in action).
One of my favorite projects is his exploration into sports garments and equipment, called Spoetry. He claims that the project "promotes self-expression by modifying sports gear", but a more interesting outcome that he hasn't articulated is that his augmentations force the wearer to interact, move and gesture in the exact opposite way that was intended in the original product (they also happen to be gorgeous). For example, when two people are riding on a bike, the person in the back normally sits facing the person in the front so they can hold on and see where they're going. His tandem bike helmet forces the passenger to sit facing backwards, stripping them of the ability to see where they're going and to hold on for dear life.