Getting the Most Out of SSH

jfruh writes "If you have to administer a *nix computer remotely, you hopefully ditched Telnet for SSH years ago. But you might not know that this tool does a lot more than offer you a secured command line. Here are some tips and tricks that'll help you do everything from detect man-in-the-middle attacks (how are you supposed to know if you should accept a new hosts public key, anyway?) to evading restrictions on Web surfing." What are your own favorite tricks for using SSH?