for example I want to make a cover for my 808 to be able to put it still on a flat surface and around the camera I would do some adapter for phone lenses (macro/wide/fisheye)

and maybe on a side a female screw for tripod mount

and cover door for lenses...

and maybe here should be links to where you can print your creation (I found this in my town: http://www.printare3d.ro/preturi/index.php); or maybe local teams of Nokia should have 3D printers and go with your creation to your local Nokia and print it (of course for a price)

anyway this idea is awesome because the phones now-a-days are just a screen and back cover... for example with 820 cover you can totally change your phone... for example make-it curvier or more oval and you won't see it because the join is near the screen... let's hope that this is the first step to an entire phone customization - even hardware like PCs are...