I think there have been attempts at trying to create Gecko-like adhesives like this: http://en.wikipedia.org/wiki/Geckel. But I am pretty sure there are a lot of details that Geckos have evolved/optimized for - surface area/shape of their setae/legs, angle of contact from their hyperextended toes, ability to stick in different humidities etc. - that would be difficult to recreate for football receivers on the field to actually take advantage of Van der Waals forces.