1 billion. That’s the metric for December 2008 when the Internet hit the big 10 digits. The number comes from ComScore. To put it in perspective, MIT’s “Internet Growth Survey” says that we hit the 1 million mark in 1995.

By the way, that 1 billion number doesn’t include those coming to the Web from Internet cafes, mobile phones or PDAs.

EMarketer has different numbers that point to even more users online. By employing a slightly broader audience definition – access by anyone of any age from any location – the company estimates that there were 1.172 billion Internet users worldwide in 2008.

China has the most number of Internet users worldwide, said EMarketer senior analyst Lisa Phillips, followed by the U.S., Japan and Germany. She expects that India will eventually hit the number two spot.