You can make FaceTime calls not only from your iPhone or iPad, but from your Mac too. This means you can use it with anyone else using an iPhone, iPad, iPod touch, or Mac computer that also supports FaceTime. It also doesn't eat into your cellular data plan like FaceTime calls over cellular do, which makes it an even better option for when you're at home.
FaceTime for Mac is incredibly barebones right now, almost no UI chrome or options but we'll see what happens come release. The ability to stay in contact, visually, from any iOS or Mac OS device is compelling, but it would be even better if Apple released a Windows version. Let's hope that's coming soon.
As promised by Steve Jobs during Apple's Back to the Mac event, FaceTime for Mac beta is now up on Apple.com and available for download:
FaceTime for Mac makes it possible to talk, smile, wave, and laugh with anyone on an iPhone 4, iPod touch, or Mac from your Mac over Wi-Fi. So you can catch up, hang out, joke around, and stay in touch with just a click. Sure, it’s great to hear a voice. But it’s even better to see the face that goes with it.