Pre-Paid SIM cards
I travel with this collection of prepaid SIM cards ... one for every country that I visit regularly. In most countries, a prepaid, unused SIM card account does not expire for at least 6 months of non-use, and typical costs for a card are $1-$2 USD, with a "load" of talk time costing as little as $1. ...and incoming calls have always been free in almost every country (except the US). So I always have a working phone as soon as I touch down. Also, data services such as Internet browsing are working (you just pay more if you browse the internet a lot) rather than being a special "service" that you have to turn on for a fee. Typical costs for domestic calls in most countries is around 10 cents a minute for a prepaid account.
When I visited the US, I gave up on trying to buy a prepaid SIM card that included data services along with voice...from what the Best Buy salesperson told me, it would cost hundreds of dollars for a couple of months ... unless I had a "contract" (post-paid) account with Verizon/T-Mobile or whoever. So Third World.....
Meanwhile, in a so-called "developing" country like....Cambodia...I can buy a prepaid SIM card on the street for about $2 (the yellow one that says HELLO in the picture is from Cambodia - this small country has 5 cellular operators!). It has all services working, including 3G with download speeds of almost 1 Mbps (that's what I measured). I put $10 in my Philippine SIM and have been using it for data services only ... after 2 months of browsing, I still haven't used up the $10. Notice the Australian SIM that is pre-cut for iPhone use.