So I have a question that 'm pretty sure many others out there also have. With different wattages and same connectors are these MagSafe adapters compatible with each other? My wife has a 2008 13" MacBook Air, my son has a 2010 13" MacBook Air, and I just got a 2011 11" MacBook Air. I know that the 13" runs on 50W MagSafe power adapters, but are they all compatible and interchangeable? Will it work or will it damage anything? Thanks in advance!