Yesterday I read from Jennifer Martinez at www.gigaom.com that the Blackberry Curve won best selling smartphone in Q2 this year.

In the battle of the smartphones, RIM’s Blackberry Curve edged out the competition to take the top spot as the best-selling smartphone model in the U.S. in the second quarter of this year, according to inaugural smartphone market share data from research firm IDC. Apple’s iPhone 3G S took second place, with the iPhone 3G placing fourth.

She continues:

With its hard QWERTY keyboard and big screen, the Curve (a longtime favorite of Om’s) has stood the test of time and beat out higher-end competitors such as Apple’s iPhone, Palm’s Pre and T-Mobile’s G1. Although the iPhone being limited to the less-than-stellar AT&T network likely plays a role in these rankings.

Apple Inc. and Research In Motion Limited / Blackberry are the top six sellers.

IDC compiles the list by counting vendor sales to mobile carriers, consumer electronic stores, online retail stores and independent distributors, and excludes counting the sell-through to consumers (so thankfully for Palm, the Pre’s creepy commercials don’t play a factor in the results).

This is a horse race I continue to appreciate. Both firms are dedicated to continuous product improvement. Both firms are challenged in the networks they choose. In the northeast Verizon (VZ) is superior but receives the smartphones last, AT&T (T) has all the iPhones but drops too many calls (at least in the northeast).

As a portfolio manager, I am clearly rooting for both sides.