i would never clock it, the good thing about theese cards is that they have fast chipmem and so on, basically u wont benefit anything at all on clocking it to lets say 66mhz, other than lame memory speeds.
060 on the other hand allready is slow in the department so clocking it to 66mhz aint that noticeable really, but u notice it on games/demos and stuff that neeeds more cpu power! (even if the memory is dog slow)
just a suggestion anyway...