We're using 'rancid' (http://www.shrubbery.net/rancid/) to backup the configs and track changes of all our switches. Rancid is basically an automated ssh/telnet connect tool that grabs the config and stores them via CVS - with a web-based front-end to look at the configs or changes.
I had to make minor modifications to the "..login" and "..rancid" scripts to make them work properly with EXOS