FoxyProxy
FoxyProxy is a free, open-source advanced proxy management tool that completely replaces Firefox's limited proxying capabilities.
Proxy Lists
You are encouraged to run your own private proxy if you have access to an unrestricted ISP. However, for those who are not so fortunate, here are some sites that maintain lists of open proxies around the globe. These proxies can be temperamental, so you will be better off running run your own private proxy if possible. We have no affiliation with these sites.
Rosinstrument - huge resource of proxy lists, tutorials, FAQs, etc.
www.TextProxyLists.com
XRoxy
SamAir Security
MultiProxy List
Proxy4Free
AtomInterSoft socks and non-socks
PublicProxyServers.com
CoDeeN, Princeton University's Content Distribution Network - neither private nor anonymous but reliable. HTTP proxies only (no SOCKS), all of which listen on port 3128.
Proxy Services
SilentRevolt