From http://www.opera.com/freedom/ HTML source code comments:

We start our little story with the invention of the modern day computer.
Over the years, the computers grew in numbers, and the next natural step in the evolution was to connect them together. To share things.
But as these little networks grew, some computers gained more power than the rest and called themselves servers.
Today, millions of people are connected together in a great web …

Wonder what they have for us ? Check it out in 30 min
http://www.opera.com/freedom/

Edit:

Opera Unite: a Web server on the Web browser

http://unite.opera.com/

Take control of what you share online
Opera Unite allows you to easily share your data: photos, music, notes and other files. You can even run chat rooms and host entire Web sites with Opera Unite. It puts the power of a Web server in your browser, giving you greater privacy and flexibility than other online services.

Share with other Web browsers
What if you use Opera at home, and a different Web browser at work? Opera Unite services can be accessed from any modern browser, including mobile browsers! At home, just select what you want to share, and you can view it later using your work Web browser without any problems.

Integrated and extendable
Simply enable Opera Unite when you start Opera 10 beta, and you are ready to go. Find and install services with one click from our online catalog or easily create your own by using Web standards like HTML, CSS, JavaScript, SVG and AJAX.