Figures for the first quarter of the year from market analyst NPD Group reveal that RIM's Curve models have benefited from a 'buy one get one free' offer from Verizon and taken the number one spot.
"Verizon Wireless' aggressive marketing of the BlackBerry Storm, and its buy-one-get-one BlackBerry promotion to its large customer base, contributed to RIM capturing three of the top five positions," said Ross Rubin, director of industry analysis at NPD Group.
"The more familiar, and less expensive, Curve benefited from these giveaways and was able to leapfrog the iPhone due to its broader availability on the four major US national carriers."
RIM has increased its market share in the smartphone market to nearly 50 per cent over the past quarter, while Apple and Palm have each lost 10 per cent.
Smartphones now make up nearly a quarter of handsets sold in the US, NPD reports, up from 17 per cent this time last year.
"Even in this challenging economy, consumers are migrating toward web-capable handsets and their supporting data plans to access more information and entertainment on the go," said Rubin.
RIM had three of the top selling smartphones, with Apple in second place and T-Mobile's G1 in fifth.
New regulation expected to cut greenhouse gas emissions by about 17 million metric tonnes between 2020 and 2050
Molybdenum ditelluride is a two-dimensional material that can be easily stacked into multiple layers to create a memory cell
New light-guiding nanoscale device can control and monitor a nanoparticle trapped in a laser beam with high sensitivity
Optical traps are scientific instruments in which a focused laser beam is used to exert an attractive or repulsive force on a microscopic object to hold it in place
Scientists estimate that the exoplanet has already lost up to 35 per cent of its mass over its lifetime