Ping!
I had reviewed this iPhone Application at my website and even created a international Ping! Directory.
For people who don’t mind getting into this band wagon to know more people, feel free submit your Ping! UserID here to so that more people can ping! you.
Finally you can find more people to know at this NEW INTERNATIONAL PING! DIRECTORY
One trick I usually do is to turn off the sound for the push notification but it’s fun to know more people! 
