S-terminal lets you create a secure X terminal. Regular X terminals pass unencrypted data between you the remote machine. S-terminal creates an encrypted tunnel through which all X traffic passes. It replaces the remote xdm login screen with a local application that collects username and password, then sets up an ssh tunnel to the remote host and starts a session. It is highly configurable both in appearance and behavior, and deployed S-terminals can be remotely administered. Best of all, it can be added to a KNOPPIX CD to create an instant, bootable, secure X terminal CD.
Diagrams don't work everywhere
Unfortunately, the "diagrams that just work everywhere" say "browser is not supported" when used with Mozilla 1.7.13.