I was asked today about how many I.P addresses there could possibly be, considering each computer on the net needs a different I.P.
an I.P Address looks like this 123.123.123.123 thats they go from 0.0.0.0 to 255.255.255.255 that is 255 to the power of 4 or 255 X 255 X 255 X 255 this gives us 4228250625 or 4.2 Billion I.P address' possible, that is a lot but with more and more people using the internet they will, in our lifetime run out, Meaning not all people could connect at once.
There is light at the end of the tunnel though, as this 4 octet i.p addressing system is already being replaced and a new system is already with us, if your running vista you've already got it.
It's called IPv6 as opposed to IPv4 we currently use. The I.Pv6 looks like this 2001:0000:0000:FFD3:0000:0000:0000:57ab
this gives us wayyyy over 340282366920938000000000000000000000000 I.P addresses, I don't ever think we will out grow that. With 6.5ish Billion people alive in the world today (dead people don't surf) We would be ok with that many addresses...