Opera provides a free online tool called Opera Mini Simulator that emulates the Opera mobile phone browser on your desktop computer. The tool is done in java and is quite popular among web designers for testing website layouts on mobile phone devices without actually using a mobile phone.
As you probably guessed it by now, this Opera Browser Simulator can also be used for accessing web pages that may be blocked on your computer. Since the requests are made via the Opera.com website, they would easily bypass the local filtering.
To open any site in Opera, just append that site address to the following URL and start browsing.
http://www.operamini.com/demo/?url=[URL] - example
The Opera Simulator can even be used for secure sites that require cookies - for instance, you can check your Hotmail emails via Opera. Though you are restricted to the tiny 200x200 screen of Opera simulator, it's still a very handy tool. [Opera link