A website for identifying birds
There are actually a few, the problem with these websites is that they usually cover only a part of all birds on this planet. I use:


Bird identifier: Usefull website for a lot of European birds.
Backyard Bird Identifier: Useful for some European birds but
mostly for North American and Canadian birds.
All about Birds: Useful, but needs more knowledge for the identification


What I also do is using Google with a description of the bird, which sometimes works surprisingly well.