I've seen a few folks asking about the Scala Rider Q2 headset/intercom so will share my experience.
Helmet: Nolan N102. There's a Nolan intercom option for it, but $$$ and mixed reviews.
Phone: Crackberry Curve 8310 with bluetooth
GPS: TomTom 720 with bluetooth and fm transmitter
I figured I'd have some trouble getting all this gear to talk to each other, and I was right.
I installed the headset in the helmet pretty easily. The electronics pod clamps onto the side of the helmet; reasonably secure but definitely a bit of a kluge. I powered it up and confirmed that the built-in FM radio was working. A bit awkward to change stations or volume, but it sounds ok (despite the dual speakers, unit is mono). Supposedly has active volume adjustment to account for road noise; have not tried on bike yet. Electronics pod pops off of clamp; I'll probably remove for rain events (it is claimed to be "rain resistant" - in my experience that just means that it will last a bit longer than something that isn't).
Unit paired up easily with my Crackberry. Can answer or initiate calls from the helmet. Not a high priority for me but I figure if I hear a call come in I can pull over and answer without pulling helmet off and searching for phone. Phone would not send music to the helmet, though - apparently Crackberry cannot send music to any bluetooth devices as configured.
And GPS would not pair up with helmet at all. But I guess I can use the fm transmitter to send spoken directions and music to the helmet if desired.
Have not yet tested the intercom. If this part works as designed, would make for a nice intercom or bike-to-bike communications option. Claimed range is "up to" 500 m.