The folks at video4skype have produced a free plugin for Skype to allow a video stream to be sent along side a skype-skype call. My exstensive ( two days ;) ) testing looks good, the quality is fine depending on bandwidth. It does the traditional picture-in-picture view, I'm hoping to use this quite a bit when I'm on the road later this month to keep in touch with the kids.
I've bought a little webcam from Creative to clip onto the laptop when I'm roaming. Its a great little toy that packs away into a very small bag provided with it.