The world is a strange place. Dog eats dog seems to be the rule, and then... not necessarily so (*). The following tools are offered to the public free of charge, under various licensing schemes. Behind them are different and often differing conceptions of intellectual property at stake. Offered below are links to the homepages of useful software titles.
TCP/IP tunneling through HTTP. Proxy must support CONNECT. Useful to bypass internet censorship and restrictions (some countries, your workplace, etc.)
Excellent terminal console supporting SSH and proxies (including SOCKS). Ideal for logging into remote unix accounts.
Proxy which filters and rewrites HTTP headers and HTML content. Blocks ads, popups, browser information... Supports proxy chaining.
Same as above, but simpler.
Tor is a network of virtual tunnels that allows people and groups to improve their privacy and security on the Internet.
HTTP and FTP retrieval tool. Command line tool (*).
Submit internet search queries (*) through email. Type help in the subject of the message for information on query syntax and use.
Internet specific script language.
"In the beginning was the command line", Neal Stephenson's essay (or zipped)
"Homesteading the Noosphere", by Eric Steven Raymond.
Fravia's search lores
Waynes and publicproxyservers.