Keyboard mapping utility?

[FullmetalZ26]

I have one of those old IBM "Model M" keyboards that I've been typing on for probably the past 10 years hooked up to my Mini (1.42) via a PS2-USB adapter. I changed the command/option/control keys to my liking in System Prefs, but it's kind of irritating that the Inst/Delete/Home/End/PgUp/PgDn keys don't work like they're supposed to. For example, despite not having regularly used a PC for 2 years now, I still try to select everything in text boxes by pressing Home, holding Shift and pressing End. Does anyone know of a decent (preferably free) utility that would allow me to map these keys to act as they are labeled? Thanks for any help!