Based on complaints about the factory power adaptor in this and other forums and advice from a Mac owning friend, I bought Kensington's model 33079 while I was waiting for my PB to arrive last year. It's my normal power supply in the US and I've used it all over the world and in more airline seats than I care to think about. Apple's offering is still in the box but I get it out sometimes 'cos it feels cool.