Depends on the chip itself, what options your motherboard has, and what RAM you got.
If you've got a 133MHz front side bus P3, you're probably not going to get as far as if you had a 100MHz FSB P3. Also, AOpen hasn't been a company that comes to mind regarding overclocking, and since I don't know the exact board you've got, I can't say how much you'll be able to take the CPU. I will say that if you don't have an adjustable CPU voltage, you won't get very far.
Another factor that can put a cap on how much you can OC is what core you have. If you have the older Coppermine core, you're about at it's limit. If you've got the newer Tualtin core, you might get a decent OC out of it, pending other factors.