Came across an interesting article on TechRepublic:
http://blogs.techrepublic.com.com/networking/?p=2491&tag=nl.e102At this time, there are about 402 million address left, but...
The IPv4 addressing scheme consists of a 32-bit address space. According to RIPE that means IPv4 address space is 32-bits (232) in size and contains 4,294,967,296 addresses. At the time of this article, my iPhone app showed that 402,291,729 addresses (9.4 percent) remained. According to the app’s count-down meter, all the addresses will be gone in 593 days.
I guess we'll have to learn IPv6... yuck!