Sitting down with two executives from Symbian, provider of the world's leading mobile-phone operating system, and analyst Avi Greengart of Current Analysis at the CTIA Wireless show in Las Vegas gave me a feeling of déjà vu.

Every year at the Smartphone Summit, it seems, officials from Symbian -- which enjoys a dominant market share of nearly 78% of all smartphones in Western Europe, but has less than 3% in North America -- explain how they're going to conquer America as well.

These efforts to date, as Greengart put it unkindly, have "faltered," largely due to the inability of Nokia -- the world's No. 1 handset vendor and Symbian's primary OEM partner -- to make significant headway in the U.S. market.

"We've always said that the U.S. market is different" from Europe and East Asia, said David Wood, Symbian's executive VP for research. "And we expect after a while it'll change. There are very definite changes happening this year from last year: it's clear that there is no longer a separate smartphone corner" in carrier retail stores, he added. The carriers have "realized there is big money to be made" selling these more sophisticated devices.

Even so, I ventured to say, does Symbian really have to compete in a U.S. marketplace that continues to fragment, with Windows Mobile devices, the iPhone, and forthcoming handsets based on Google's new open-source platform Android all competing for shelf space and consumer attention?

"America hits beyond its weight," Wood said, meaning that what happens in the U.S. mobile market has a disproportionate influence elsewhere. "The U.S. is a natural market for high-end smartphones," he added, "it's just taking a while for that market to develop here."

That's almost certainly true -- and it will be interesting to see if the Nokia/Symbian S60 platform, so compelling in non-U.S. markets, will gain significant share on these shores.