Well, i would say the max you really want a processor to stay at is 55c IMO. although, it also depends on what voltage you have going through your processor and obviously stability.
http://www.cpudatabase.com/CPUdb/ <-- shows tons of OC's on many many processors, you can look up the 2000+ up there.
also to consider is unlocking the processor, which can allow you to drop the multiplier and raise the front side bus (FSB) higher, usually offering higher performance. one thing to look out with higher FSB's is however, the components in your AGP (vid card obviously) and PCI components. they were in a 2:1 ratio (AGP 66mhz, PCI 33mhz).
if you can lock the agp and pci to a set point, then thats good, otherwise you'll probably work with ratios. if its too hgih, you're definitely going to have an unstable situation, and can damage components.
voltage is another thing. your bios will enable you to raise the voltage in .025v increments. in order to yield decent results, you'll most likely have to raise the voltage. i'm not too familiar what the maximum should be for athlon processors voltage wise, htat you could ask an AMD type.
for testing stability and temperature (temperature should be measured at full load), i would advise using Prime95 and/or Folding@Home client to test it. then go to task manager and make sure the processor is at full load. in prime95, you're system may become pretty laggy. once you've settled on a frequency, i would leave it in prime for overnight or an entire day to test stability and to let it 'burn in'. meanwhile, i would get a program like MBM or something similar (e.g. something that came iwth your motherboard) to monitor temperatures.
GL and HF oc'ing your processor and don't break anything
![:\](/images/smilies/submitted/smark/ohwell.gif "Oh Well :\")
