Code is attached to this post, feel free to use it for your projects. Constructive comments welcomed.
The SerialPortHelper class is very easy to use. Just instantiate it (you can overide its speed, etc, but you don't have to):
1. ReadLine() method returns a full line or a blank string coming from serial port.
2. Print() and PrintLine() prints a string to serial port.
As mentioned in the second video. I believe there is a bug, but I have never seen it happen in real life yet. If you know how to fix this, please post. Thanks!!!
http://www.youtube.com/watch?v=Os3bOCWbmHA
Demo of Netduino's SerialPort communication capability.
http://www.youtube.com/watch?v=gUB6UFyDkaA
Second video explains the wiring and reviews the actual code.
PS: Chris, If doesn't qualify as a project "Showcase", feel free to move it to more appropriate forum.
EDIT: 10/26/2010 - Attachment updated to add Locks and declare interruptPort as static.