If you watched closely at Tim Cook's keynote today, amidst all the other new goodies to come out of the Worldwide Developers Conference in San Francisco, there was an easter egg of sorts: Apple has slipped in a new FaceTime Audio feature to its beefed-up iOS 7, and it brings iPhone owners one step closer to — well, to not really ever needing a phone plan.

Despite the confusing name, which still inexplicably includes the word "face," FaceTime Audio is basically a phone call without a phone carrier signal. It's like FaceTime without the video part, meaning that it runs on Voice Over Internet Protocol — just like iMessage. In other words: People who already don't use their phones for calling very often can make phone calls without using pricey minutes, siphoning away even more cell-phone time from our increasingly Internet connected phones.

Calling without the calling plan is a feature that already exists, most famously with Skype and more clandestinely in Facebook Messenger, but baking it right in to the iPhone's calling software makes the transition from talk-time minutes to WiFi that much easier. The FaceTime button is right there, a click away from each contact on your phone. FaceTime Audio doesn't require downloading a separate app, nor does it require finding other people you want to call from those apps. You just have to go to your contacts, and your iPhone will determine whether your contact also has FaceTime Audio, presumably by highlighting an icon like the one pictured at right. (So get your friends to upgrade, you sneaks!)

Apple's subtle move doesn't push carriers out of the picture completely, of course: Some wireless companies allow FaceTime over their data networks. But anything users can do over WiFi cuts into the necessity to buy plans with a lot of data or with any standard minutes, especially as WiFi becomes an ever-present option. And, of course, phone companies have already started to respond to these changing user habits, making phone plans more unlimited data-centric as customers have stopped caring about a hard count on talk minutes or text messages. We will always need our phone companies to use our phones — just less and less as we shift from calling and texting to doing all that stuff over the web.