Sorry, KBolt...
I don't know where you get your information, but it's just plain wrong. Sure, there will always be overhead and most people will never see the full speed of their internet connection because of that, but there is no general 20-30 megabit per second cap.
I have seen download/upload results of 195.42/53.53 megabits per second (200,120 kbps download, 54,820 kbps upload) - and that's on university computers, which aren't typically bleeding edge machines.