This isn't the first time this has happened, but rico mossesgeld on The Smart PDA, another blog in the Creative Weblogging network, has quite a find: the iPod Touch and iPhone can be given a SIP stack to make VoIP calls.

SIP is an open standard that makes it possible to make voice over IP calls. Oh sure, there are other ways to do this, but SIP is the most widely deployed and used. Once you get a SIP stack and can route the audio input and output correctly, you can theoretically make and receive calls over IP.

It looks like the development work on this is still ongoing, but it warms my heart to see the hackers continuing their quest to tear down the walls Apple has erected around their device.