mac981:
Thanks for the feedback.I should have stated the range basically the further the better. Current similar units state 60meters, we need to be better so i kind of ruled blue tooth out
I don't know whether WiFi would cover that range, but depending on the environment it might do. In that case you could just use a WiFi shield.
If that doesn't work, you do have the option of using GSM. You'd need to buy a data plan for it, but it would give you effectively unlimited range as long as you stay within phone coverage and as long as you don't mind a bit of latency.