With the advent of good non-dry batteries almost all the electronic gadgets come with in-built batteries that need to be charged and used. It is much common these days to see three to four different adapters hanging out of the electical sockets in any house.
Why can't there be any standards enforced on the adapters? Most of the gadgets requires 9v/12v DC input. And at any point of time, no one is going to use more than two. If one single type of adapter could be used for multiple gadgets, it really eases the pain a lot.