GNU httptunnel

httptunnel creates a bidirectional virtual data connection tunnelled in HTTP requests. The HTTP requests can be sent via an HTTP proxy if so desired. This can be useful for users behind restrictive firewalls. If WWW access is allowed through a HTTP proxy, it's possible to use httptunnel and, say, telnet or PPP to connect to a computer outside the firewall. httptunnel is written and maintained by L

[apeman]

proxy経由でトンネルが掘れる cygwinパッケージあり

[karronoli]

httptunnel本家ページ

[harupong]

httptunnelのホームページ