I'll give you it's possible to use ssl key authentication for automatically logging into cisco devices, but that's not an option via telnet, and if you've got more than 600 devices that you don't remember which small subset are still on old enough code they don't yet do SSH, this can come in handy.

When you're dealing with hundreds or thousands of devices and need to make a small change to a large number of them, there's no way to accomplish that without using something like expect; at least I don't know of one now. If you do, please enlighten.

-Scott