Here’s a cool project that lets you display text on a dot matrix LCD via an ethernet connection and web interface.
Using an AVR microcontroller driving a standard HD44780 LCD display, this project provides a standard ethernet interface for your projects. You can send text to the unit, which would be useful for weather stations, e-mail count displays, and other such displays from your computer. Of course, you can use standard programs or web interfaces to capture the data that needs to be displayed.

There appear to be enough leftover pins on the AVR microcontroller that you could rig-up a nice switch matrix for complex input or even use a few of the pins for output to control relays or other circuits. Overall, this LCD display project gives you a nice foundation to begin building your own projects on and saves you the tedium of learning TCP/IP communications and other low-level stuff.