Ok, so it seems that the PHP RPM that installs with Mandrake doesn't include PEAR, even though the version of PHP installed should. (That or I'm missing something obvious here)
I poked around pear.php.net for how to install, came across instructions to install the pear download manager by running
lynx -source http://go-pear.org/
from the command line. I do this as root (assuming it would be needed to install), and sure enough the pear install program launches, prompts for the various directories and packages desired, then appears to run the installation.
All items downloading, bootstrapping, and all show OK, but after the install completes, there is no hint of PEAR anywhere on the system. I looked in the directories specified during install, and there's no hint of the programs (either the pear installer, or pear.php for that matter).
Is there something I'm missing here in the process?