Access your virtual computer from any place
Web 2.0 and new technologies coming along with it caused a big boom of advanced online services that were often able to substitute software installed on your own computer. Taking security and privacy concerns aside that naturally arise when using such services on the web people got used to it rather quickly and several web 2.0 applications saw a huge burst in users shortly after they could be used by anyone.
Thanks to AJAX and similar technologies many complex personal web-based desktops have started to appear lately. After creating an account on such sites you could create your own virtual computer and access it from anywhere by simply connecting to the Internet and using your default browser. I tested two example services in the last days: The first service that I would like to mention is a service called OSX Mercury that is a completely free service.
Although this service looks very nice and interesting I didn't actually test it because I was disappointed that the only supported browser is Firefox; I use Opera. That's why I did not test it but if you're a deep-rooted Firefox user, give it a whirl. The site seems to be down as of know due to a large amount of users that wanted to use their service.
The second similar service I found is a free web desktop environment called GCOE X, a Unix-styled system remotely accessible from anywhere. The thing is that you can only test the service as a demo user at present. Creating your own account and using all features should be possible soon as they're claiming. This could be a fine choice for existing Unix users as they would have an advantage in handling this system. A Unix bash seems to be an important part of the project in the testing mode.
Update: The service is no longer available.