[ChainReaktion]

As someone with neither the background nor the mathematics to fully understand renormalization, I'll say that the wiki entry isn't terribly helpful:

"Renormalization, in this example, mathematically replaces the initially postulated mass and charge of an electron with the experimentally observed mass and charge."

That sure sounds like adding an arbitrary constant into your theory and turning the knob until the theory matches the results. The comments here suggest that's not the case, but it's easy for me to see where the skepticism comes from.