When I owned a car, I never put extras on it to draw attention to myself.
But now that I bicycle just about everywhere and I'm always worried about my visibility -especially at night- I've decided no gadget is too much for my bike as long as it draws attention to me.
So with that in mind, I bought the Monkey Lectric spoke lighting system. Bring on the bling!
The product just went on sale in May and the company is aiming it squarely at the hipster/fixie crowd, not the commuting set, but I went ahead and took the risk to buy the $70 product.
What is it exactly? Well, it's 10 or so ultra-bright LED lights in a row on a reinforced/water resistant circuit board that attaches with zip ties to your spokes.
Powered by three Triple-A batteries, the system blinks different colored patterns at random, and once you get up to speed (12 mph -20mph), that pattern then appears to create a solid light disk inside your wheel.
I installed it on my Swobo Dixon last night and immediately went for a ride.
It works great! Not only did it create an almost completely solid circle of light at about 15 mph, but it lights up the pavement around you. The effect is really remarkable.
But best of all, it really does draw the attention of motorists. In fact, I had three drive along side me just to watch the light show, which I figure is good since they know I'm there.
Anyway, I realize it's not for everyone, and I wouldn't dream of putting this on a race bike or something like that, but as an auxiliary lighting system, I think you could do a whole lot worse.
If you do get one, make sure to install the system with the batteries closest to the hub of your wheel. If you don't, it can really throw the wheel off.

15" exposure at night in my garage
Link with much better pictures