Info is info. Here's a copy:
A) Install Opera
1) Download Opera, choose Ubuntu as the distro: http://www.opera.com/download/
2) Open a terminal and navgate to the folder where the Opera .deb file resides.
3) Type sudo dpkg -i opera<tab key>.deb. Pressing the tab key will fill in the rest of the overlylong unix filename for you. If you get a dependancy error message type sudo apt-get -f install.
4) Right-Click on the desktop and select Create Launcher (shortcut). In the command section browse for Opera in File System/usr/lib/opera/8.fxxxx/opera. The icon is in /usr/share/opera/images. Right-click on your new Opera icon and select add to panel.
5) In Opera select from the menu tools/preferences/advanced/network/proxy servers/. Tick the box in the HTTP section and type 127.0.0.1 for the IP address and port number 8118.
B) Install Tor
Open up a terminal and type sudo apt-get install tor
C) Install Privoxy
1) Open up a terminal and type sudo apt-get install privoxy
2) Type sudo gedit /etc/privoxy/config and paste the following line at the top, including the full stop: forward-socks4a / localhost:9050 . Save the file.
D) Switch between direct and anonymous mode
1) Tor and privoxy start automatically on Ubuntu sytems. To browse or post anonymously in opera select Tools/Quick Preferences/Enable Proxy Servers
2) Test your privacy, visit http://www.ipbrowser.net/. If your ISP internet provider doesn't show up you're anonymous! Browsing will be slower but your IP is only recorded when you post, not when you are just reading. Tor servers may be operated by the security services of various countries too so don't use Tor for very strong anonymity.
For Firefox users
Start at point B. To switch to anonymous mode go Edit/Preferences/General/Connection Settings/ and tick Manual Proxy Configuration. There is a FireFox plugin to switch between direct and anonymous mode SwitchProxy. As before the details of the Tor proxy are 127.0.0.1 port 8118