The recent GPS/IFR discussions here got me to thinking. I generally fly an
Arrow, equipped with a Garmin 430, 2 VORs, Loran, my handheld GPS, my
sectionals, low enroute charts, and since I got my IFR ticket, I try to
fly
under ATC control as often as possible to keep my comm skills up.

On cross county flights, I fiddle with the VORs and cross check my
location,
I set the Loran (if it's working that day), etc. In other words, for
navigation, I use everything inside and out the cockpit that is
operational.

Which one is considered primary?

The one providing course guidance on your HSI. If you're not HSI equipped,
its the CDI somewhere in the cockpit that you use for course guidance. If
you use a bunch of stuff at the same time, then the question doesn't mean
anything.