Everyone in the USA seems to think that the USA is way behind everyone else in mobile usage. When I was there last month, though, it seemed that they have a very high level of mobile usage - for voice, at least. Here in NZ, voice calls are pretty expensive, so the main usage of mobile phones is for text messaging. Just about every high school kid or university student has a phone, but they very rarely use them to call people. It costs me US$0.30 per minute to call a landline or another cellphone on the same network, or US$1 per minute to call another cellphone network -- so I don't do it unless I really have to.
Update: Ashish picks this up and talks about petrol prices in the USA, NZ and India.
After reading that I went back to check up on NZ cellphone prices, just in case I was unintentionally exaggerating there, but no, it looks like I was right. Here's the actual pricing plan I'm on: "motormouth prepay".
If I was on the contract plan, it would be a bit cheaper - $40 (US$28) for 200 minutes, so US$0.14 per minute (if I used them all). I spend less than $40 monthly anyway, though, so it wouldn't be a saving for me.
Here are all their other plans. I think the "motormouth on account" plan is the cheapest overall, except that it only gives you cheap calls to other Vodafone mobiles - it's the "network lock in" plan :-)
It looks like the other main NZ mobile provider's charges are exactly the same.
As for petrol prices, pricewatch.co.nz maintains a continuous survey of petrol, diesel and LPG prices around NZ from info gathered from purchases on petrol account cards. In Canterbury (where I live), the current lowest prices are:
98 octane - NZ$1.529/L - US$4.05/gal
96 octane - NZ$1.489/L - US$3.95/gal
91 octane - NZ$1.439/L - US$3.81/gal
(1 gal = 3.785 L and NZ$1 = US$0.70, so US$/gal price = NZ$/L price * 0.70 * 3.785)
Note that these prices include all taxes - as all advertised prices in NZ must, except for airfares (although travel agents and airlines are finally starting to display taxes in advertisements).