Remember when all you needed on your bike were a few stickers, a basket, and color-coordinated streamers that matched the Barbie motif? If you were one of the fancy kids, you got a matching bell. I was not a fancy kid...
Bikes, especially in big cities, are serving a less recreational, more utilitarian purpose. With gas prices as they are, the cost of reliable cars being unattainable for many, and traffic being more and more aggravating (especially in Memphis, but that's a MUCH longer story), bikes are becoming a more viable mode of transportation. Why not outfit your 2-wheeled ride with the accessories you REALLY need?
Basket - okay.
Streamers - ironic, but amusing.
Baggage storage - necessary.
Horn/Bell - try riding WITHOUT some way to let drivers know where you are!
Bottle opener - YES!!!
If you're like the bike messengers I know, you're a beer fan. Enjoy.