Who can you facetime with the Iphone 4?

My friend has the Iphone 4 and I'm getting the Iphone 4s soon. I read that Iphone 4's can only Facetime with other 4's. Is that true?

No, an iphone 4 can facetime ANY OTHER iOS DEVICE THAT HAS FACETIME. This is true as well for any facetime-enabled ios device.

Anyone in your contacts and you must have permission from the account owner (email its hooked up to) and they must have a apple device and must be in your contacts (with their email!)

No it's not you can FaceTime anyone with apple products 4th generation and up
iPod, iPhone, and all ipads, Macs

It's in the Phone app, or you can go to Contacts and do it from there.

No. Any iPhone 4, 4S, 5, iPod touch 4G, 5G, Mac desktop/laptop can FaceTime with one another.