Google finds 1 trillion URLs on the internet

I read an interesting post in Google's Official Blog, Google has found 1 trillion (thats one followed by 12 zeros) unique URLs on the internet. This number has grown from 1 billion in the year 2000.
It was just yesterday that I could finally Google my blog and around the same time Google finds 1 trillion sites on the web, maybe it could just be that my site is the 1 trillionth site in this world to get indexed [:P].

Google finds and index pages by following through links to reach other sites. It says that there are actually more than 1 trillion sites it has found but they are not unique and contain copies and so it cannot say the exact number of unique URLs out there. And not every 1 trillion pages get indexed, since many of the sites are similar to each other and represent auto generated content.