NRC - Mobile Web Server: "For quite some time it has been possible to access the Internet using mobile phones, although the role of the phone has strictly been that of a client. Considering that the modern phones have processing power and memory on par with and even exceeding that of webservers when the web was young, there really is no reason anymore why webservers could not reside on mobile phones and why people could not create and maintain their own personal mobile websites."

There seem to be a few folks out there now turning things on their head by embedding web servers everywhere (as opposed to thinking of wirelessly connected devices as just clients): Node and Ambiesense, amongst others...