OK, so today I bought a second 65W power adapter for my PowerBook since it was starting to get annoying having to unplug t from my desk area, and it was starting to look ugly from all the traveling . So now I have another one, which I don't plan on moving away from my desk area, and will always be plugged in whether connected to the PowerBook or not. But then something came to mind... The thing comes with 2 connectors. The tiny 2 prong, and the 3 prong cord. So which one would be the one to use as a "Permanent solution"? Since I don't plan on digging in the back of my desk and bother with the adapter once I install it. I'd rather not have yet-another lengthy cable back there, and it would still reach with the 2 prong. But then again, there's got to be a reason one is 2 pronged and another is 3 pronged. Why wold Apple give us a choice on this? What's the incentive for using the 3 pronged cord (Especially since 3 prong outlets are harder to find?) EDIT: I know what the 3rd prong is for, grounding. But what comes to mind (To me) is the fact that we have a 'choice' and thats what I'm wondering (Why we have that choice).