The term Technological Singularity refers to the creation of computers or artificial intelligence with greater than human intelligence. It was first suggested by Vernor Vinge in 1993.  Some have humorously dubbed it "Rapture for nerds".
The theory discusses the acceleration of technological progress which has been the central feature of the past century, and claims that we are on the edge of change comparable to the rise of human life on Earth. The precise cause of this change is the imminent creation by technology of entities with greater-than-human intelligence. Science may achieve this breakthrough by several means, and Vinge claims that this is another reason for having confidence that the event will occur before 2030.
The rationale for the theory is:
- Computers that are "awake" and superhumanly intelligent may be developed. (To date, there has been much controversy as to whether we can create human equivalence in a machine. But if the answer is "yes," then there is little doubt that more intelligent beings can be constructed shortly thereafter.)
- Large computer networks (and their associated users) may "wake up" as superhumanly intelligent entities.
- Computer/human interfaces may become so intimate that users may reasonably be considered superhumanly intelligent.
- Biological science may provide means to improve natural human intellect. 
"An analysis of the history of technology shows that technological change is exponential, contrary to the common-sense 'intuitive linear' view. So we won't experience 100 years of progress in the twenty first century—it will be more like 20,000 years of progress (at today's rate)."
- An article was presented at the VISION-21 Symposium sponsored by NASA Lewis Research Center and the Ohio Aerospace Institute, March 30-31, 1993. For details see http://www-rohan.sdsu.edu/faculty/vinge/misc/singularity.html
- Full paper available at: http://www-rohan.sdsu.edu/faculty/vinge/misc/WER2.html
- Kurzweil, R., (2005), The Singularity is Near: When Humans Transcend Biology, ISBN 0670033847,