John is a silly, silly boy...not only would Rodney have been happy to have made him web-shooters, he also would have badgered Carson into making an artificial version of whatever caused the effect so that he could have neato superpowers too.... and additionally, the whole science team would have pooled their resources to create a nifty costume and gadgets and Super!Shep-mobile...oh, wait, that's the Jumper, isn't it?