As of 31st of March 2011 the amount of people using the internet passed the 2 billion mark (2,095,006,005 to be exact) or about 30.2% of the world population.
Asia makes up 922 million with Europe the next closest at 476 million and North America at 272 million. North America may only have 272 million internet users but that is 78.3% of the population of North America, which is by far the highest percentage of total population.
So when you are on the internet and it suddenly slows down, check what time it is in North America or Asia, because it might not be all the people in this country slowing the internet 🙂
Statistics courtesy of www.internetworldstats.com.