Follow your interests. It's not perfect and you do need to stay on top of things; I'm a heavy user of lists and persistent search tags. But you could also use

Follow your interests. It's not perfect and you do need to stay on top of things; I'm a heavy user of lists and persistent search tags. But you could also use a service like http://getlittlebird.com http://getlittlebird.com to find people in a specific field.