Apple's Power Nap, which allows Macs to pull down email, calendar changes, software updates and whatever else from the internet while in standby, is now available as a firmware update for those running Mountain Lion.
9to5mac reports that the firmware allows those running OS X 10.8 Mountain Lion to take advantage of the feature. One snag, though: you'll need either a 2011 MacBook Air or better, or one of the new 2012 Retina MacBook Pros. The firmware update for the MacBook Airs is already available, and the Retina update is "coming soon". You can read more about Power Nap's features here.
Sadly, standard MacBook Pro users need not apply. Apparently the option should spread to more of Apple's laptops as the company transitions entirely to SSD. In the meantime, Air and Retina users will be able to open their laptops to find things have happened while they've been stowed away—which is either incredibly cool or just the tiniest bit creepy. [9to5mac]