I accidentally posted the following in a reply on the MBP forum: My Penryn 2.4 MacBook has an airport card that runs >70C at all times when enabled. I can just have the laptop idle and iStat will report a temp from 70-72C. Under heavy transfers it will only go up to maybe 73C. My wife's Penryn 2.1 MacBook which I got at the same time as mine has a card that idles in the mid 50s and then goes up to the 70s under stress. I don't get it. I've tried rebooting, checking processes, etc. Anyone have any ideas? The left side of my MB stays warm all the time because of it.