After several years in the making, the camera tool for Canon SLRs has finally been released for the 7D.
Magic Lantern is a firmware hack for Canon SLRs that equip them with extra functionality for stills photography and video recording. The Canon 7D has long been one of the only cameras that the community hasn't been able to hack, because it runs dual image processors.
Features accessible on the 7D with Magic Lantern installed include:
Audio meters during recording
Live View settings, including brightness and contrast
The additional functionality is accessed by the camera through the memory card, and needs to be loaded from the card every time you want to use it.
As with all Magic Lantern hacks, use this one at your own risk; it is not officially supported by Canon. To download, head to the alpha release page over at Magic Lantern.