Stripped yum repository for updates?

[Horvath Andras]

Hi,

I have 3 machines, each running FC2. I connect to Internet through a
broadband router with a 384kbs cable modem. I decided to install a yum
repository for updates on one of the machines to prevent triple
downloading of rpms. 

However I recognized that in a yum repository containing updates there
are very big amount of old packages (e.g. a lot of version of kernel and
kenel-sourcecode) and only the most up-to-date is needed. 

How can I avoid downloading the unneccessary (updated) update packages?
Are there any solution exists? (A script or a repository which is
continuously stripped down to keep only the most fresh versions?)

Thank you in advance,

András