FaceTime, the excellent video calling application originally introduced for the iPhone 4 has now been released in beta form for the Mac.
Open Facetime and you'll immediately see yourself on screen, and you have to sign in with your Apple account to get started. Once done, FaceTime will sync with your address book, allowing you to immediately call anyone who has the capability.
Calling an iPhone 4 or iPod Touch is easy, once you have your contacts. Image quality is excellent, and the display is pleasantly free of distractions. If the iPhone is rotated, the image also changes on FaceTime for Mac, from landscape to portrait and back. It's a very smooth, simple and comfortable video call experience.
FaceTime is not perfect though. While integration with your contacts on the iPhone makes perfect sense, on the Mac it's less useful. You can't add contacts to FaceTime directly, but have to do it via Address Book. If you don't use Address Book, you have to start. Hopefully integrating contacts will improve in later versions, and perhaps include other services like Facebook. It would also be nice to have FaceTime open without constantly seeing video of yourself!
FaceTime is a very promising video chat application that's certainly the best option between Apple users who are able to use it. However, it still needs more development, and will struggle to knock Skype off its perch unless a Windows version is produced.