An extremely small, full function embedded network server.

Olimex has created a fully functional TCP/IP embedded server which they claim is the world's smallest PIC-based TCP/IP server. Using the board's included network stack and ethernet port, you can use the board to serve web pages, retrieve FTP data, send e-mail or anything else that is port based.

The possibilities for something like this are immense. A few ideas come to mind. You can use the on-board microcontroller to collect temperature or other data and upload it to a server. You could build an alarm that will e-mail or SMS you if it's tripped. You could make a streaming audio receiver. Stick it on your keg-fridge and have it serve a webpage showing the beer temperature, number of glasses served, and other critical keg information I could see using these in a home gameroom/arcade to track how many games are played or communicate coin-in/coin-out of home-use slot machines. With a full TCP/IP stack, this embedded controller could do lots of things.

The pricing information is in the page title (odd, I know) and says that the PIC Mini-Web, unit is only $39 in single quantities.