What he said :-)
RPM system as most linux package methods are static compressed file containers, not true installers (Even if such ones exist in linux, as for amsn for instance). This because there is not yet a truie common standard for installers.
So actually, "legacy" application packages usually install in /usr (/usr/bin for binaries, /usr/lib for librairies, /usr/share for data associated to the software, as the web templates for amule, or translations ...), and "one shot" or "trial" usually go in /usr/local (That I do with my CVS packages).
Plus the RPM packages may install too updates for menus. Here's the main difference in RPMs specific for Mandriva, as the menu system it uses is not the RedHat definition, but something inherited from Debian, and with specific tricks to be used in all installed desktops.
This way you'll find amule and other binaries from the package in Internet/File transfer, for CVS as for legacy ones. And they will be in these menues in KDE, Gnome, AfterStep, Windowmaker, Enlightment, fluxbox, IceWm, FcWm, etc.