There are a number of motherboards available that support FSB as well as multiplier adjustment in order to pave the way for overclocked Duron/Thunderbird systems. Such boards include the ABIT KT7-RAID and the ASUS A7V, unfortunately, the motherboard can't do everything, in order for the motherboard to be able to take control of the CPU's FID and BP_FID multiplier pins, the "Golden Bridges" present at location L1 (below) must all be connected.
Most newer CPUs will be like the 1.1GHz shown above, where the bridges present at L1 aren't joined. In order to join them, some conductive epoxy or a very fine tipped conductive pen can be used to connect each one of the four bridges. Afterwards, your motherboard, provided that it does have multiplier control, should be able to adjust the clock multiplier of the CPU.
A Thunderbird with the bridges at L1 connected
There have been reports of Socket-A CPUs that feature even more attempts to prevent remarking, however we have yet to see any evidence of this first hand. We will keep you posted on anything we do discover.