If you want to make a Qt application capable of serial communication with an Arduino, then these are some great resources to do so:
* QextSerialPort : cross-platform serial port library
* Arduino Serial reference : awesome Arduino documentation
I had some trouble getting the QextSerialPort library to work with VS 2008, so I will just go over all steps I needed to take.
* Run this command in the QextSerialPort directory: qmake -tp vc : this will make a .vcproj file from the .pro file
* Open the .vcproj file with VS 2008
* Change the configuration type from dynamic library to static library [as the original setting did not produce a .lib file]
.. and you are ready to go.