This technique creates a great illusion of continents. The same technique can be used to make whole maps or simple globes. This tutorial will just show you how to automatically generate a map/globe.
Create a circle and fill it with a light gray color.
Go to FILTER>>RENDER>>DIFFERENCE CLOUDS. It is okay if it doesn't show up that well.
Next go to IMAGE>>ADJUSTMENTS>>LEVELS and move the handles toward the area with a lot of "Spikes".
Your image should start looking like a globe. Finally go to FILTER>>SKETCH>>NOTE PAPER.
Final Result