For anyone interested in clever networking hacks, I strongly advise checking out ptunnel. This software package allows you to tunnel any TCP (such as SSH) over a ICMP (i.e., ping). Since even the most restrictive firewalls (whether corporate, Wifi (don't steal...) or other) usually let ICMP traffic through, this little piece of code can let you access anything you want.
The latest formal release is 0.61, but there's no formal Windows version available. There are two ports of 0.52, but they don't support the authentication found in the newer versions. If you want to run this on a public server, you'll almost definitely want to be using the authentication.
The pingtunnel-win32.diff file can be applied to create a version that compiles for Windows. It relies on the WinPCap library (I tested with 4.0.2; just unzip into c:\Program Files\), and MinGW. After applying the patch, instead of running make, run "mingw32-make ptunnel.exe".
This second diff file, pingtunnel-syslog.diff, can be applied to add syslog support. If you want to run this as a daemon, you'll probably want syslog support so that you can see the output.
I've sent these patches to the author; hopefully they'll make it into 0.62!
