3. Polipo (web proxy)
The main difference when compared with the traditional Tor bundle is that OperaTor uses a specific browser (which is obviously Opera) and uses Polipo instead of Privoxy as a web proxy.
The best part is that OperaTor is aimed to be portable and can be run from your USB or portable disk drives. All configurations and settings will be saved on your portable device instead of on the host machine you are using it on.