csshX is a tool to allow simultaneous control of multiple SSH sessions. csshX will attempt to create an SSH session to each remote host in separate Terminal.app windows. A master window will also be created. All keyboard input in the master will be sent to all the slave windows.
Download link: https://code.google.com/p/csshx/
An very simple example:
csshx --login tester hostname1.com hostname2.com hostname3.com hostname4.com
mxiayan 