One of the things that is so great about bikes is their simplicity. You don't need electricity and a lot of fancy stuff, a few lights for night and you are on your way. But then it is nice to see what is behind you... and a GPS unit would be helpful...oh, and what about a heart monitor? It is all here in this new Cerevellum rear view monitor for around $299, which is 50 bucks more than I paid for my bike.
http://www.cerevellum.com/