We noted yesterday that claims that Comcast's invisible cap is 90GB were incorrect. Today, you've got the Consumerist insisting said cap is 200GB -- which also isn't necessarily correct. While 90GB or 200GB caps may exist in some markets, they aren't the system-wide limit since, technically, the caps change based on congestion and vary from market to market (sometimes as high as 500-600GB). More interesting in the article is an insider's claim that Comcast has a "pay-by-the-GB" overage system already tested and ready to roll:As we mentioned last week, there's plenty of people in the industry who'd love to shift to a bill-by-the-byte model as a way to address "bandwidth hogs." But which provider wants to be the first to implement such a system and face the marketing wrath of its "unlimited" competitors?