Cuil (pronounced as COOL) is the Search engine launched by some Ex-Googlers and I found it really cool. Search results are really relevant and a smart way of presenting the results for any search. It has the biggest index on the internet. It (www.Cuil.com) has indexed 120 billion web pages, three times more than any other search engine (mean what? Google!).
And after this announcement, Google asserted on its blog Friday that "the web is big" and Google system hits a milestone which is 1 trillion (as in 1,000,000,000,000) unique URLs on the web at once!
Now, lets take an example. I made a search for the keyword "SEO" for this -
Cuil has 64,639,623 results for SEO and Google have 237,000,000 for SEO
Now, you can yourself see the difference.