[CentOS] auto-creating a local yum cache?

Hey folks,

I just did an update on a system that is taking the better part of a day (
5.3 ---> 5.7 ) mainly due to file download times.

And I have 4 or 5 more systems to do.

I know I can create my own repository and then point them at it - but that
is difficult here because rsync is blocked (ggrrrrrr...)

Surely there must be a way to have yum on the first box automatically cache
everything and then have the other boxes use the cache?   Maybe if not
directly, then with squid or something like that?

Anyone happen to have done this before?

thanks,
-Alan

-- 
“Don't eat anything you've ever seen advertised on TV”
         - Michael Pollan, author of "In Defense of Food"