Reading this thread I found out that you can power on the rpi from idle by connecting gpio3 (pin5 revB) to ground, tested it and it works great.
I didn't read that anywhere else, including in the basic or detailed gpio documentations so i was wondering where it was documented.
And if it's actually undocumented, if there's a source for undocumented gpio features on the rpi?
So far I only knew you could power it on from idle using the unpopulated reset pins but as it acts as a true reset switch and I don't want to use that as a power button.
Well I now have an onboard power button, with the help of a shutdown pyhton script which I was already using, fantastic.