Peru - Cell phones in Peru

I would like to have cell access during an upcoming trip to Peru. The plan so far is to spend a few days at an as of yet unchosen lodge near Iquitos and a few days in Cusco/Machu Picchu. I assume that there is cell access in Cusco, but what about the other places? Is there a preferred company for SIM cards?

Quite honestly, I am getting tired of collecting SIM cards from various countries. Does anyone have a recommendation for a global SIM card that really works? I understand the minute rate would be high, but so is buying SIM cards that all seem to expire in 6 months.

Thanks.

If you have part of a business day in Lima (or maybe even some time @ LIM during business hours), you may consider just buying a prepaid phone. I have done this in Chile - and spent only about $50 and it came with more minutes than I could use. When I returned a year later (and the unused minutes and phone # expired), I went back to a branch of the provider in Santiago and recharged the phone for a modest minimum sum and got a new #, etc. with no extra fees. Something to consider.