hmm - we've seen this on here before - its all a bit of marketing spiel as its just regular old cameras that has had conventional outputs scanned in at very high resolutions on conventional film scanners. technically you could take any posi/neg - even a polaroid snapshot - output and scan it on a high end drum scanner and call it a gigapixel image....sorry! maybe Santa could drop you something else more fun :-)
I have already come up with my own still life and landscape large mega pixil camera design. My partner and I are working on it lets just say it invalve a scanner and a very large belowes and a medium format lens.We've already have copyrighted the design we can't copy right the components next if possible is the patent. But thats a cool 25.000 that will take a while to get together. We are working on the proto type at this moment.