You might want to look into the Teensy 2.0 (OR 3.0) . It has hardware USB support, uses the Arduino IDE, and is very simple to use.
It is similar to the Arduino Leonardo, where the chip supports HID, but has many more libraries and easy-to-use features.
Teensy Joystick Examples
Teensy 2.0 - $16
It's definitely worth a look
