That's a shame it hasn't been coded. It'd be fairly simple to take an already coded project such as a python wallet and change that to have this interface. Or even just use an API to a hosted wallet site in order to get this information.
I'd also suggest that instead of having addresses, the user instead has "labels" that they can select. So if you want to send something to someone you coud use something memorable like a 4 digit number relavent to them, their name or even a phone number that is linked to that address so it can be sent easily.
That is quite a good point that the 64mBTC would be 8 times the size of the 1mBTC one so it is proportional.
You could also then probably have a way of changing from ^3 (3D) to ^2 (2D) and ^4... (although ^4 may be hard to visualise unless the graphics can rotate).