Why is Google called 'Google'

The goal of Sergey Brin and Larry page (the Google founders) was to create a search engine that could hold the entire world wide web, and to make it accessible extremely quickly to the public. The name Google comes from ‘googol’, which is a very large number; a 1 followed by one hundred '0's. They had to modify the spelling since googol.com was already taken.

If you use Google frequently you would have noticed how they often play around with the logo, this is one of the things that makes Google 'friendly' and somewhat welcoming. Here is an example of the Google logo modified for Halloween:

"Now you can search the equivalent of a stack of paper more than 70 miles high in less then half a second...- we think that's pretty cool." Larry Page