cssh - cluster ssh - do your cluster work easier

This is a very simple but powerful tool for interactive work with many machines at once
Just log in to them

cssh node1 node2 node3

and do the same operations on all of them.

It needs x-window (mmm, just wonder if there is a pure-text replacement?) and it is worth to configure ssh keys and perhaps ssh-agent to make your logins easier but still safe.
cssh comes with packages for ubuntu/debian, not sure if redhat/centos rpms catch up here. This project page is http://sourceforge.net/projects/clusterssh/
Many thanks for this tool!