Thanks for everyone who has contributed thus far. These are, in fact, RPMS that I'm dealing with--sorry for neglecting to mention that earlier. I've taken a look at RPM::Update (part of RPM-Tools-0.8). Running this code should have the effect of finding and downloading updates:

RPM::Update::execute('-v','-ftp', 'my.ftpserver.edu/mirror/ftp.redhat.
+com/pub/redhat/linux/updates/8.0/en/os','-d', '/tmp/rpm-download','ch
+eck','-dl');
[download]

Unfortunately, I keep getting told "No new updates are available on my.ftpserver.edu". I removed a couple of packages from my system and installed the 8.0 release versions of them (specifically, xpdf and cvs) before running the script, so it should have been able to detect the updates. I'm not sure if I'm doing something wrong here or if the module is simply failing to recognize that updates are, in fact, available. And for the record, I did double check my URL, the existence and permissions of /tmp/rpm-download, and that updated xpdf and cvs packages were available. I even used ethereal to watch the packet stream...I succesfully logged in to the server and got directory listings, so it's not something in the ftp transaction.

Any more thoughts? Can someone point out something I'm doing wrong here?