mi Lite, from Blue Box is a protective graphic skin that features tiny sensor switches that make your iPod light up and go blinky-blinky like a Christmas tree when you hold it in just the right spot. There's a nice selection of graphics, although the lights themselves appear to only come in blue. They'll set you back less than $20 and are available for all iPods except the iPod mini and iPod shuffle. The lights are powered by a "replaceable power source," so as not to drain power from your iPod.
What ever will they think of next in the land of gratuitous iPod accessories?