Hi Heli_Fella,
we use HeliMap with HeliComm from eae - link posted before
or download their broshure
http://www.eae.de/pdf/helicomm_en.pdf
http://www.eae.de/pdf/helimap_en.pdf
Works quite well and all you need is an internet computer with the software installed, to track the birds, see where they´re going (destination from helimap is displayed) and send them messages.
Its all done by so called SBM (short burst message), which reduces the amount of traffic via the Iridium phone.
Helps quite a lot if you work very low, where normal transmissions won´t reach you.
Grretings Flying Bull