On Monday a project that I've been working on was officially announced as part of a larger privacy initiative called Polaris. In case you missed it, there is an experimental tracking protection feature in Firefox Nightly that allows people to avoid being tracked by not communicating with known tracking domains, especially those that do not respect DNT. Our initial blocklist is from Disconnect. As a side effect, blocking resources from tracking domains speeds up page load times on average by 20%. Privacy features rarely coincide with performance benefits, so that's exciting.
Currently, tracking protection is available by turning on browser.polaris.enabled in about:config. If you care about privacy in Firefox and are running Nightly, please give it a try. Requiring about:config changes is quite onerous, but we need your feedback to improve tracking protection. You can read official instructions on how to turn on tracking protection or see the animated gif below (original slide deck here for people who like to advance manually).