[Tor][] is an anonomizing proxy, see their list of [usage
scenarios][use] if you want more details.  A basic Tor client is
extremely easy to set up on Gentoo, just emerge `net-misc/tor`,
possibly tweak the stock `/etc/tor/torrc`, and fire up the connection
with

    $ sudo /etc/init/tor start

which (by default) opens a [SOCKS][]

To use your new Tor "proxy" with Firefox, go to
`Edit->Preferences->Advanced->Network->Connection->Settings->Manual
proxy configuration` and set

    SOCKS host: localhost
    Port: 9050
    Version: SOCKSv5

To use remote DNS, enter `about:config` in the address bar, set the
filter to `dns`, and set `network.proxy.socks_remote_dns` to `true` by
double clicking.

To disable cookies, which would allow the sites you're connecting to
to track you as your exit IP changes, go to
`Edit->Preferences->Privacy`, select `Firefox will: Use custom
settings for history`, and make sure `Accept cookies from sites` is
unchecked.

To check that everything is properly configured, you can browse over
to [Tor's check utility][check].

[Tor]: https://www.torproject.org/
[use]: https://www.torproject.org/about/torusers.html.en
[SOCKS]: http://en.wikipedia.org/wiki/SOCKS
[check]: https://check.torproject.org/

[[!tag tags/linux]]
[[!tag tags/tools]]