It’s no secret that Americans love their smartphones. In fact, most of them would probably be lost in a sea of boredom and confusion if they were separated from them for a day. One report suggested that 50% of people aged 18-34 own a smartphone, and that number is on the rise. In that same survey, 60% of people would give up TV before giving up their smartphones.

One in three would even give up chocolate, forever, to keep their smartphones.

But not only do people own them, but they use them a whole lot – for high-consumption activities it seems. Nielsen analyzed cell phone bills of over 65,000 smartphone owners and found that data usage has skyrocketed in the last year. In Q1 of 2010, the average smartphone owner used 230 MB a month. In Q1 of 2011, the average smartphone owner uses 435 MB – an 89% increase year-over-year.

Top consumers continue to grow their consumption at an even faster pace as the top 10% data users grew their consumption 109% and the top 1% of data users grew their consumption a whopping 155%.

What type of phones are people consuming the most data? Overwhelmingly iPhone and Android powered devices. The average Android owner users 582 MB per month and the average iPhone owner uses 492MB. Both increased year-over-year from around 312 MB. Windows Phone 7 data usage shot up last quarter while Blackberry data usage stayed pretty low in comparison.

It looks like the giant app stores available to iOS and Android users are to blame.

The study also reports that cost per MB has shot down to 8 cents this quarter compared to 14 cents back in Q1 of 2010.