Anybody,
There is plenty of information out there on this issue in the forums and on anandtechs site. But any way for the SlotA athlons the goldfingers device works best for changing the clock mult. For the socketed Tbirds and Durons Get a board like Abit kT7 or Asus A7V which have multiplier controls (one software and one hardware). Also if you get one of the socketed processors you may need to connect the L1 bridges with pencil or other means as discussed on many hardware sites. The Bus on these setups is not very agreeable to overclocking in my experience. I have several of these setups.
Tbird 900 on Abit kT7 @ 1050mhz
Duron 600 on Abit kT7 @ 950mhz
Original Athlon 550 (hard mod) on MSI 6167 @ 850
Original Athlon 550 (goldfingers) on Abit KA7 @ 750