According to a new report from JiWire, more people use iPhones to connect to public Wi-Fi hotspots than any other device. Those users stay connected for over an hour, and mostly visit social networking sites.JiWire put together an extensive report on how Wi-Fi was used across the U.S. for the first six months of 2009. Some of the results are surprising.

First, where is everyone using Wi-Fi? Well, 55.3% are accessing Wi-Fi at hotels/resorts, 27% at airports, 10.5% at cafes, 4.4% on cruise ships or ferries and 2.7% on public transportation.

About 56% of respondents admitted to hitting up cafes more than once per week, and a sizable 46% said that they stayed for one to two hours. According to JiWire, 38% of people are trusting enough to make purchases on the Internet via public Wi-Fi hotspots.

The really interesting stuff is what users are, well, er, using to access the Internet at cafes. A majority 54.2% of all mobile devices to access Wi-Fi in places such as cafes are iPhones. The iPod Touch follows, with 43.4%. In other words, Apple devices make up for a whopping 97.6% of all mobile devices accessing Wi-Fi at cafes. That's incredible. (This doesn't include laptops.)

This really makes me wonder, do other smartphone users know that their devices have Wi-Fi? Are they just not interested in using the Wi-Fi? Does the sheer volume of AT&T-supported Starbucks Wi-Fi hotspots play a role, where iPhone users have free access?

As more smartphones and devices have Wi-Fi on board, it will be interesting to see if/how these statistics change.