According a new report from Nielsen, detailing a three month period ending this past July, smartphones now make up 40 percent of all mobile phones in the United States. Android has increased its share among smartphone users in the United States by 1 percent, brining its total slice to 40 percent.

iOS continues to hold 28 percent of the smartphone market, while Windows Phone and Windows Mobile combine to grab 8 percent. RIM dropped a point and currently holds 19 percent of the market.

According to the same report, when smartphone users were asked which operating system they want in their next smartphone, iOS still trails Android. Interestingly, though, iOS shows significantly higher results than its current market share, which could suggest significant potential growth in the future.

Now that the iPhone is available on Verizon as well as AT&T, and with rumors of Sprint on the horizon, more users now have the ability to choose an iPhone with their next contract upgrade than ever before. As wireless contracts expire, and a larger pool of customers get to pick between the latest iPhone and the latest Android phone, it will be interesting to see if the market share changes as well.

Via BGR

Adrian covers daily news as well as the weekly Law & Apple column for MacLife.com. You can follow him on Twitter, if you want to.