Having been a Flarm user for years I can tell you it is a install and
forget device. The portable device(for initial contest use) will
probably not be integrated into your PDA so you would just make sure
you have good batteries, mount it with the EZ-lock or what ever and
turn it on. It will see other Flarm units in the area, and it will
give you collision avoidence alerts when you go flying. Pretty much
right out of the box. Yes, setting the ICAO address is good but in the
rental contest situation it is not necessary. Don't make this harder
than it has to be. Get the rental units to the Contest staff (along
with lots of EZ-lock strips and batteries) and have them hand them
out. Have a safety meeting with training on what to expect from the
Flarm unit and how to install/operate and go fly.

The first time I saw Flarm was when it was installed in a club plane I
was flying. Did a winch launch, got a warning, looked at the display
(for probably a second) and then looked out to see the glider that the
Flarm was warning me about. SOLD! I would have seen this plane but
Flarm saw it first. From that point forward I will not fly without a
working Flarm unit.
Some lessons he
Flarm works and alerts you to Flarm equipped planes you have not seen
(yet).
I hadn't been "trained" on Flarm but when I saw the display I knew
where to look.
I have yet to meet a glider pilot who does not "Get" the Flarm concept
after flying with Flarm. (of course some still haven't bought a unit
yet but I don't know anybody who doesn't fly with one) PEER PRESSURE
WORKS WELL.

Get the Flarms into the contests, get them into club planes, then
you'll get them into the other planes.

You may not (ok, probably don't) agree with all of this but until you
fly with Flarm you don't know what your missing! Litterally! Ask
anyone who has flown with Flarm. John Cochrane?

Bob