Hello,
I updated the Interfacing with Software Wiki page with a much easier out-of-the-box start using Visual Studio 2008 Express Edition to communicate with Arduino over serial. It has been a long time since I wrote a low-level program, thus, it would have taken me forever get serial communications working. For those that don't want to spend any money, and aren't software savvy, this is probably the quickest way to start hacking with serial communications.
It's located here: http://www.arduino.cc/playground/Interfacing/CPPWindows#VisualStudio2008
I do just reference an existing Arduino sketch in the steps, but in the future I'll create a stand alone example. It took me about 15 minutes (after installing VS2008 ) to get this working. I'm sure you can replace "C++" with any other .NET supported language and it'll work fine. I think I might experiment with doing this through a webservice.
I will be looking to expand this page: http://www.arduino.cc/playground/Code/VisualStudio
So that you can create, edit, compile, debug and burn code to the Arduino. The idea is you will be able to create a solution with two projects in it: PC side and Arduino side. This way should provide a much lower "cost to entry" to full hacking capability of the newest users!
Here is a very brief outline of the steps: - Download and Install Visual Studio 2008 C++ Express Edition - Create a CLR "Windows Form" Project - Add Serial Port interface for your board - Create controls on the form and send the data to serial port. - Create Arduino code to receive data