Smartphone users, including Apple iPhone owners, generally download five software applications each, according to market researcher InStat.

The small number of downloads appears to be at odds with the heavy use of Apple's iPhone App Store.

The online store has been so popular that Apple put out advertisements in early December saying the number of downloads had hit 300 million in the short time it had been open. The store opened on July 11 of last year. Projections were that it would turn into a $1bn business.

iPhone 3G review

It still may, but the store has not changed the fact that smartphone users overall, including iPhone users, tend to download an average of five apps each, a trend InStat says can be seen across many different mobile OSs.

Apple iPHone downloadsBut people with iPhones are by far the heaviest mobile web users, at least in the US, according to researcher Net Applications.

The company measured mobile internet browsing and web search from handsets and concluded that 66 percent of people on the mobile web are iPhone users.

The next five rivals down the list are all in a close battle for second, with Java ME holding the spot with a 9.11 percent share, Windows Mobile in third with a 6.9 percent share, Google's Android software in fourth with a 6.26 percent share, Symbian in fifth with a 6.17 percent share and Palm with a 2.37 percent share.