If you're in Boston this summer and see a funny device hanging off a pooch's collar, don't be surprised. A startup called Snif Labs, which grew out of MIT's Media Lab, is testing a technology designed to help dogs--and their owners--become better acquainted. When dogs wearing Snif's tags come within range of each other, the tags can swap ID codes. When the dogs' owners get home, they can use the company's social-­networking service to trade information about their dogs and themselves. Your dogs have made a connection, the thinking goes; maybe you'd be willing to share advice, dinner, or more. Already, dog owners can meet online through canine-centric websites. "The Internet gives people the freedom to share information; the dog becomes a kind of online avatar," says Ted ­Rheingold, founder of ­Dogster, a social-­networking site for people and their dogs. Snif's tags import the same idea into the real world. Snif--which stands for "social networking in fur"--also lets humans use the Internet to monitor the activities of pets left at home.