The term "ping" is well known to people who manage computer networks. It's a method that's used to determine if another computer on the network is responsive.
It can also be used in another type of networking context, though: personal networking. For example, here's another excerpt from that useful article on master networking that I cited earlier:
Eighty percent of success, Woody Allen once said, is just showing up. Eighty percent of networking is just staying in touch. Ferrazzi calls it "pinging." It's a quick, casual greeting. He makes hundreds of phone calls a day. Most of them are simply quick hellos that he leaves on friends' voice mail. He sends E-mail constantly. He remembers birthdays and makes a special point of reaching people when they have one. When it comes to relationship maintenance, he is, in the words of more than one friend, "the most relentless, energetic person I know."