yi.org is a Dynamic DNS Provider. Dynamic DNS Providers give you a convienent way to access your computer, no matter where in the world you are, or how often your computer moves around or changes IP addresses. If you want to run a webpage from a home internet account (most of which use Dynamic IP addresses), get a free .yi.org hostname for a small project instead of buying one, or travel around the world with your laptop, hosting a live webcam feed whenever you can plug it into the Internet, yi.

Above text was excerpted from: http://www.yi.org/help/about/