Thanks for the comments but not a solution for me!
As standard, on my 987.2 Boxster 2009 model, non-xenon, when the DRL function on the computer is activated, then the dipped headlights and tail lights are on.
I followed the instructions for the Utkinpol hack and with the light switch in the 'off' position, it didn't 1) turn off the dipped beam, 2) turn off the taillights, and 3) did turn on the fog lights which I wanted to use solely as DRLs.
However, with the diode still in place, I deactivated the DRL function on the computer and got no lights with the light switch in the 'off' position but in the 'home' position, it works as I wanted - fog lights as DRLs and no tail lights on. The fog light logo on the switch is on too.
Otherwise, the lights work according to the switch position, and the 'home' functions correctly also, with just the fogs on.
So Im a happy camper! I did a similar hack on my 2000 model Boxster S which was a little more involved with a relay and a less sophisticated wiring system.