http://tychoish.com/rhizome/9-awesome-ssh-tricks/
收藏了，但英文头大

Control Master/Control Path 第一次见，Reagent第一次见，
其它的在 奥莱理的「SSH权威指南」都有讲述。

还有这个也顺便推荐给不用OS X的同鞋, cygwin也能用: http://www.funtoo.org/Keychain
Keychain helps you to manage ssh and GPG keys in a convenient and secure manner. It acts as a frontend to ssh-agent and ssh-add, but allows you to easily have one long running ssh-agent process per system, rather than the norm of one ssh-agent per login session.

gentoo keychain我想了好几年也没想明白到底有啥用

同步文件版本功能很弱