What are the concerns with oc'ing the cpu?

Other than temps, is there anything to keep in mind? Can you go as high as you want just as long as its cool enough, or is there a concern with high clock speeds?I ask because right now i have a core 2 e6600 going at 3.478 GHz and the highest the temp gets is 56C. Whats to say I couldnt go higher? Also, what is it that determines the temps, the clock speed or the voltages? What are the concerns with oc'ing the cpu?
Artifacts... unstablility... BSOD... Keep it at that its high enough jesus! You speed whore :PWhat are the concerns with oc'ing the cpu?
[QUOTE=''LouieV13'']Artifacts... unstablility... BSOD... Keep it at that its high enough jesus! You speed whore :P[/QUOTE]could you please expand on those. Everything has been stable but how would i tell if there was some other issue?(yeah, my speed is fast, thats why im asking about this)
[QUOTE=''StaticFriction''][QUOTE=''LouieV13'']Artifacts... unstablility... BSOD... Keep it at that its high enough jesus! You speed whore :P[/QUOTE]could you please expand on those. Everything has been stable but how would i tell if there was some other issue?(yeah, my speed is fast, thats why im asking about this)[/QUOTE]

Well I wouldnt know I never had or read anything about C2D but I would keep it at that speed
mainly it will decrease your cpu's life span, because its working harder, its wearing faster. also remember that before a cpu is released to the market it undergoes extensive testing, i have a friend that work for intel doing just that, writing programs that check if the cpu is doing logically what it suppose to do. when you overclock the cpu is not working according to the way it should, and it could produce errors, EVEN if you do stress tests and the results come out good. also remember that the cpu might work fine overclocked, but after some time, few months, maybe years, it will wear down and problems will arise. if that happens don't think that just because your cpu worked fine for 7 months overclocked, its not the cause of the problem.
there is a software which u can run after overclocking ur cpu to chek its stability.I cant remember its name. it was something like ( PRIME95) i guess ....search on google for details. leave the software running overnight for better results.