So, alternate scheme for randomly generating landmass with 'percentiles' roll but without the dice. Use the stop watch function on your cell phone to get hundredths of a second; click to stop and see, click to run on. Roll under the previous number to get land, over to get seas, so we start with ocean and tend to get mostly ocean. Sum up until we get to 500 m. km^2 or whichever you want. We can still get small seas and gigantic landmass, but they're unlikely.