Although Googling takes this back to at least 2007 and the Chinese author's Web site linked in the application appears dead, I don't see this in our PS3 Downloads section yet so here goes, from the source link above:
A Chinese programmer has put together a PS3 controller driver that works with standard USB HID. That driver is called SixAxisDriver, and you can grab it right here. Simply run the install, load the driver, reboot Vista, and your controller will be identified and will start working!
This is good news I guess, but I myself already have one of those previous drivers installed .. This would've been an exceptionally good, ground-breaking news, if this driver supported the PS3 controller's bluetooth connection, hence meaning no wires even when using the controller with a PC.