The Raspberry Pi is a good choice for a webserver that will not recieve too much traffic, such as a testing server, or small intranet, as it doesn;t get too hot (so is nice and quiet), and only uses around 5 Watts of power.
Since the Pi is a basically a mini-computer, I decided to take it for a spin and see what I could throw at it, and I have been pleasantly surprised. In fact, it's been so successful that I've decided to try setting it up as a mini server with various services. In doing so, I've come up with a list of advantages that I feel are very compelling.