how do I uninstall an RPM?
I recently found out about KDE 3 and installed it, and when I rebooted, I lost my whole K menu and my quick icons..... how do I uninstall it? if I uninstall it, will I get 2.2.2 back?

just use rpmdrake, urpme or rpm -e kde3 or whatever the package name is. i'd assume that you won't get the old version back, you'd want to reinstall it. alternativly you might want to force an upgrade to an older package

rpm -Uvh --oldpackage kde.rpm

if you'll uninstall KDE you won't get back KDE2.2.2, to uninstall an rpm package
as root
rpm -e packagename
KDE comes as a bunch of RPM's so uninstalling every package can yeld dependencies, try
rpm -qa | grep -i kde
it will display the list of all kde-related packages currently installed, remove them with rpm -e command, but again it can break dependencies, and some components will require uninstalling other non-kde packages.
But before you get your hands dirty with uninstalling, issue kicker command, it should bring the KDE panel if KDE installed correctly.