I wrote a Firefox extension about 3.5 years ago called Cacheout! https://addons.mozilla.org/en-US/firefox/addon/1453
When it first came out, it got some minor buzz. Appeared on LifeHacker, was distributed with a free cd for MacWorld magazine in Italy, etc.
I haven't updated it in years and doesn't work anymore anyway.
Its been a passing thought for a while to get this extension working again. Should I do it, or just leave it dead? I stopped updating it a loooong time ago