As Apple and Verizon's quarterly earnings noted, iPhone 4 sales have been brisk. How brisk A new report put out by the NPD Group earlier today put Apple in third place in U.S. smartphone sales during the first quarter of this year.

Apple came in behind Samsung and LG, but did better than HTC, Motorola, and Research In Motion. During the quarter, NPD says Apple nabbed 14 percent of sales, due in large part to the launch of the iPhone on Verizon's network in February.

"Apple and Verizon had a very successful launch of the iPhone 4, which allowed the iPhone to expand its market share that was previously held back by its prolonged carrier exclusivity with AT&T," said Ross Rubin, NPD's executive director of industry analysis in a statement.

Rubin said some of that growth "came at the expense of the Android OS" even though phones running Google's mobile phone OS made up half of the devices sold in the three months counted.

According to NPD's data, this was the first time Android's overall sales shrunk, going down to 50 percent from 53 percent the previous quarter. RIM's BlackBerry OS share also dropped to 14 percent of sales, down from 19 percent the previous quarter. Eating into those numbers was Apple, with iOS jumping 9 points to rest at 28 percent of smartphone sales, due to combined sales of the iPhone 4 and the iPhone 3GS, both of which NPD includes in the top five sellers.

During the quarter, NPD says that unit sales of smartphones went up 8 percent from the previous quarter, with a 1 percent drop of total handset sales. With that push, NPD says this is the first time smartphones made up the majority of handset purchases in the U.S. at 54 percent of sales.

But what about the next few months A report by research firm Nielsen earlier this week found that 20 percent of those it surveyed in the U.S. were unsure about what their next smartphone purchase will be. Thirty-one percent of consumers surveyed plan to buy an Android-based smartphone in the next year, with 30 percent going with Apple's iPhone instead. Rounding out that survey was RIM's BlackBerry at 11 percent of expected purchases, and Microsoft's Windows Phone 7 platform at 6 percent.