After giving a little early sneak peek at Sprint's upcoming LTE network, PC Magazine has unveiled their report exploring the fastest wireless networks in the United States. The magazine drove around 30 U.S. cities in three cars to test the nation's five largest carriers: AT&T, Verizon, T-Mobile, Sprint and MetroPCS. Not too surprisingly (given Sprint and T-Mobile's un-launched LTE networks and MetroPCS's "not-really-LTE" network) AT&T and Verizon battled for speed supremacy, with Verizon offering faster service in 19 cities compared to 10 for AT&T.

Of interesting note, after taking their lumps early on for shoddy iPhone service, AT&T is officially the fastest wireless carrier in New York. Other cities, like Chicago, see Verizon with a distinct speed and performance advantage. Verizon still overall has a steep LTE lead, offering the service in 258 total markets to AT&T's 39.

Despite not yet launching LTE T-Mobile's HSPA+ service doesn't fare too badly in the rankings, beating out Sprint's current "4G" (Wimax) offering in most markets. Cricket didn't want to participate in the rankings since their LTE network isn't up and running yet -- probably a good idea given the fairly sad performance shown by MetroPCS in the rankings. MetroPCS didn't offer LTE in most markets, and in markets they did -- average speeds often struggled to break 2G (100 kbps) speeds.

The magazine correctly attributes a lot of the market-by-market speed challenges to spectrum holdings, something that improves for carriers like AT&T dramatically once they speed up the re-farming of existing spectrum being used for 2G EDGE services. The magazine also explored which carrier offered faster iPhone service (still only really 3G of course), noting that AT&T was the fastest, but Verizon frequently offered more reliable connectivity.

For those interested, the magazine breaks down speed winners by region here.