an application that uses the power of Google's global computer network to make web pages load faster, local cache, prefetching, data compression. Currently a Google Labs product. (probably good for very slow connections and as a general proxy)
an interactive HTTP/S proxy server for attacking and debugging web-enabled applications. It operates as a man-in-the-middle between the end browser and the target web server, and allows the user to intercept, inspect and modify the raw
a multi-purpose application level gateway, or a proxy server which runs on multiple platforms (Unix, Windows, MacOS X and OS/2). DeleGate mediates communication of various protocols (HTTP, FTP, NNTP, SMTP, POP, Telnet, SOCKS, etc.)