So this is for a the people who are worried something bad will happen to their babe their n900.
1. i overclocked my n900 since jully 7th. the day i got it. It has been running greatly. Running at 950 and the temp after using it 2 hrs internet music left angry burds running was 32.
2. If the phone cant support your overclock it will simply vibrate then restart it self. so it comes back to its stock 600.
3. if anything happens your battery dies to fast, any noobito can take the custom kernel off simply head to menu and it says "deinstall kernel".
4. You wont regret wait 679.99 on a phone anymore.
5.I did the wait that you install the kernel, then head to xTerminal and write some **** and its done and i change the overclock with the app cpufreqUI. I havent had a problem.
I strongly advise you to make sure you don't push you n900 aver 950. i was running very smooth at 750. but then i wanted to see how stable it is at 950. now its been 3 weeks its at 950 and i shut it off everynight i sleep and i turn it on with my alarm.
I love my n900. I find its better then the nexus one by a football fled. Do your research before doing the oc. maybe you might not need it. just a reflash might do the work.
At ease.

to add to this
mine has been running @ 125 - 1150MHz with the load set at ideal since May and 2 to 3 times a week it gets about 2 hours of constant streaming video and i haven't had any issues
it does get warm but its no warmer than it were @ 600MHz

dear sir where do you live if i may ask?
i live in dubai and at a normal day its over 40 degrees C
so to us who live in a hot climate i suggest never going over 850Mhz
i try to keep the temperature of my mobile at its 30ish
but it could easly go over 40 if left out :/

no need to call me sir. just call me shad. i live in canada and its around 32 in summer. i usualy change it when it gets to 33 or i shut it down for a few mins. oh yeah one question whats a warm temperature for the n900? before it gets danger zone

well shad your lucky you got the weather on your side :P
well i used it at a temperature of 45 while it was charging and playing a movie
it worked fine but remember my processor and your are not identical so no need to risk it
and the temperature sensor is for the battery so its not very accurate when it comes to

yeah, in 2 months were going to have -20 .
Not all n900 have the same processor?

I run mine since June 24/7 at 900MHz with the ULV kernel and never had any issues yet, its permanent under load.

Im running the kernel that is downloadable on application thing

my cousin just moved to MacMaster uni he says its pretty cold

they are the same
but due to difference of use by the user the processor will adapt to different frequencies in different ways

lets put it this way ... we both are human but you might like oranges and i dont

iknow its a lame example but thats the best way i can explain it :P

props to your example.