QUOTE (Realsies @ Jul 28 2009, 12:47 PM)

it's just a soft brush, most likely around 5px. You can use the pen tool to do it, but it's pretty pointless as it's more work. Just make a new layer > use your mouse (tablet preferred) and make the lines with a soft brush. Add an outer glow, erase the parts you want "under" the render/stock and you're done.
If those were done with the pen tool then the person needs some serious practice. Although like I said, I'm sure it's just a soft brush with a tablet.
Both would require some degree of skill.. I dot have a tablet but I am pretty good with the pen tool.
And it really isn't that hard to do something like that