The inevitable has finally happened. According to recent figures from market researchers Nielsen, smartphones managed to outsell their more basic counterpart for the first time ever.

According to the research firm, smartphones accounted for 55 percent of mobile phone sales in the United States in the three month period ending in May. This is up significantly from the 34 percent recorded just a year ago.

Android-based phones represented the largest portion of the market with 38 percent of the sales. Apple's iPhone and Research In Motion's BlackBerry rounded out the top three with 27 percent and 21 percent of sales, respectively.

Microsoft's up-and-coming Windows Phone 7 accounted for just 1 percent of U.S. smartphone sales. However, this figure is projected to leap frog most other mobile operating systems in coming years as Microsoft's partnership with Nokia comes to fruition.

The smartphone market's success is expected to continue throughout this year and beyond, as consumers replace their feature phones with more advanced technology and mobile phone accessories. According to recent figures from Gartner, global smartphone sales will reach 468 million units in 2011.