With 80 million users and counting, Instagram has quickly become the most addictive photo sharing service on earth. And now you can see more photos and comments with less scrolling. Like a mini social network, this app lets you see your friends' photos and like or comment on them. But the real fun starts when you use one of many free custom-designed filters and borders, from Xpro-II and Lo-Fi to Nashville and 1977. You can also use nifty tilt-shift blur effects to tinker with the depth of field.