Today, Fring (App Store Link) issued an update to its application that allows push notifications to be sent for incoming calls (as well as other IMs). This means that you can now get alerted to Skype or SIP calls even when the application isn't open, you are on a call or the iPhone/iPod touch is asleep. Therefore, your iPod touch or Phone can act more like a true VoIP phone. Fring itself is a solid IM/Voice client, though a little rough around the edges.

Another nail in the telco's coffin? We can only hope.
Comments
Tried it out
I used fring here and there before the skype app came out, but then deleted it. So I just downloaded it and gave the push a try. I'm using a 2g touch, but when I try to call my account from another one on the computer it sends me a push notification saying that "(username) tried calling you" But it wont let me actually answer the call. (maybe it works for others)
But anyways, now I will leave leave the app on my Touch so people can call and I will get the notification, then I will open up Skype to call them back. (Fring is still lacking on call quality. They say its improved, but sounds about the same to me)
The only ways this will get
The only ways this will get rid of the phone companies is to:
1. Have true multitasking so you can answer when they're calling you.
2. Ubiquitous wifi or an iPod touch with built in 3g/EV-DO card which the telcos would never allow.
Nope.
Um, the telcos own all 3g and EV-DO services . And they own the network that you plug your WIFI router into.
You'll have a monthly telco fee in either case.
Bye bye IM+ !!!!!!
Bye bye IM+ !!!!!!
Wi-Fi
Needs a wi-fi connection for push to work :-(
Don't think you need wifi for
Don't think you need wifi for push to work (just tested it) but there are other issues.
You need to have Fring running in order to receive SIP calls otherwise they constantly go to voicemail. Granted you do get a push notification, but you're going to have to keep phoning people back :-(