Great compilation of useful tips, thanks. I am using most of these options (and replaced my nc usage with the -W option). I suggest another one, in relation to the socks proxying, which is great but only works with SOCKS-enabled apps. The great sshuttle application is a transparent proxy-based VPN using ssh: relying on dynamic iptables trickery, it creates a VPN through a ssh connection. You launch the application as root on the client side, it transfers some python code to the server side (where you do not have to have any specific admin rights) and you get a VPN. It saves my life on a daily basis.