As you’re probably aware by now, Apple unveiled a new iPod touch earlier today which, among other things, brings a second device into the FaceTime family. When FaceTime was introduced on the iPhone 4 earlier this year, Apple chose to integrate it with the built-in Phone app, a logical choice considering how the company wants to present it as just another type of phone call. Apple also used users’ actual cellular phone numbers from the iPhone 4 to register devices with its FaceTime servers and allow users to place calls to each other.

The problem, of course, is that the iPod touch has no Phone app nor an actual phone number to register with the FaceTime network. Contrary to a suspicious rumor that claimed Apple would add a VoIP Phone application to the iPod touch, Apple instead added a new standalone FaceTime app to the iPod touch specifically for handling FaceTime calls. It now simply uses the user’s e-mail address to identify them on the FaceTime network, a change that has already been discovered in the iOS 4.1 betas. iPhone users who want to call iPod touch users can simply select their e-mail address to initiate a FaceTime call, although you’ll need to upgrade to iOS 4.1 on your iPhone in order to do so.

iPod touch users will also apparently need an Apple ID to actually register their e-mail addresses with the FaceTime network, but it’s not clear whether this will happen transparently as it does on the iPhone or whether the user will need to complete some type of sign-in process.

Updated: For more detailed information on setting up and troubleshooting FaceTime, please check out our new Complete Guide to FaceTime.