There is an infinite amount of URL's. This is because there are thousands of URL's added every day, and it just keeps on building up.
Improvement.
The number is not, and can not be, infinite. It's just very a very large, countable number.
Short phrases such as URLs are not copyrightable, and it is not registered as a trademark. The URL itself is registered to "Domains by Proxy" through GoDaddy.
There were approximately 638 Chinooks registered in the US in 2009. There is no official information as to how many are registered in 2013.
374,161 FAA Registered Aircraft in USA
Well, it will be impossible for anyone to count the number of urls in the world. It is like asking "how many waters are in the sea".
190 million
100000000
About 2.5 million.
8000
2622
only 20
5 million
at least 1000000