UPDATE - 15 September 2010:
Here is the second version.
No crossing lines this time, the digital pins are broken in two blocks, and the enumeration of them goes from 13 to 0.
This was my first arduino project.
It is an application developed on processing that controls arduino's Inputs and Outputs.
To use just follow the instructions:
1. Program your arduino with Standart_Firmata that is on the folder Firmware.
2. Choose your OS folder and open the aplication.
3. Choose the serial port and wait a few seconds.
4. The digital pins start on INPUT mode, if you want to change to OUTPUT mode just press 'O'. To return to INPUT mode press 'I'.
5. On the OUTPUT mode to High or Low a pin (2-7) press the little button. To use PWM (pins 3,5,6,9,10 e 11) pass over the rectangle.
If you want to modify the application you should have Processing (http://processing.org/) with the library "Arduino" (http://www.arduino.cc/playground/Interfacing/Processing) installed on your computer.
To do it just open ArduinoController.pde and change what you want.
Doubts/Comments/Suggestions/Modifications are always welcome!
PS: The pins 8 - 13 don't work on the Input and Output Digital mode, I don't know why. If you know how to make them work please tell me.