It's too bad there isn't an easy way to establish a voice connection with other people. If only there were a way to call someone without both parties needing to be logged into the same service at the same time.
There needs to be some kind of universal network that's "always on" - where everyone is just identified with a 10 digit number or something like that.
I heard there's an iPhone app called "Phone" that's supposed to be something like this, but I haven't tried it yet.
when you setup the vonage app by typing in your facebook id it gives you a checkbox to select to keep yourself logged into the network. in addition as long as the other person has the app they will get a push notification for the call either way