Renowned British photographer Drew Gardner was at Photokina 2008 this year helping demonstrate the 60.5 mega pixel, Phase One P 65+ digital back.
Phase One is a Danish company that specializes in high-end, medium format cameras, digital backs and RAW processing software.
For those of you (like me) unfamiliar with the term digital back, Wikipedia tells us that it is "a device which attaches to the back of a camera in place of a film holder and contains an electronic image sensor. This lets cameras which were designed to use film take digital photographs".
The sensor on the P 65+ is absolutely mammoth, and comes with a price tag to match, but as Drew explains (and shows us) the results are both spectacular and well worth it.