“The Ribbit Phone Component will give Rich internet application developers the ability to make and receive calls, record/send and receive voicemail, as well as add and manage contacts.”
http://developer.ribbitphone.com/
This sounds exciting, I have not tried this yet but if this component keeps what it promises it could have an immense impact on the way people communicate. I’ll update this post if/once we get access to the pre-release/beta.