Good news for Research In Motion: its BlackBerry Curve is sitting proud atop a list of the most popular mobile handsets in the US for December released by AvianResearch.

iPhone is in second place, followed by the BlackBerry Storm, LG Voyager and LG Dare.

But hang on a minute. The survey doesn't track actual sales. Instead, AvianResearch asked 100 service reps and store managers at retail stores belonging to the four biggest US operators what handsets were popular.

In other words, it's pretty subjective.

Still, it does show the continued importance of BlackBerry in the US, which is fuelling increased interest from mobile games firms in RIM's handsets.

That will only increase once the BlackBerry Application Storefront launches in March, providing an on-handset app store to sell games and apps.