The "retro film stock and effects" idea that has made apps like Instagram, iSupr8 and PicPlz so popular on the iPhone has started appearing on the Mac, now in the form of a Mac app called Lo-Fi that adds film stock, mood and frame effects to your photos and lets you share them with popular social services or store them. The app uses a intuitive "back of camera" interface and original filters to create a variety of looks, and is available for a free public beta before it goes on sale for $29.
