johnwasser:
Are you sure that avrdude (the program the Arduino IDE uses to upload to the Arduino) doesn't know how to find the USBasp device? It worked for me on a Macintosh and I didn't have to load any drivers.
Yeah, Linux and MacOS do not need a kernel driver, WinDoze does:
http://www.fischl.de/usbasp/usbasp-windriver.2011-05-28.zip