For the most recent info, see the 2011 US Cellular 3G Coverage Review
As the nation’s 6th largest carrier and a regional carrier, US Cellular 3G coverage is not widespread.
To their credit, they’ve launched a number of markets since October 2008 and have continued to do so well into 2009.
As it currently stands, it’s available in North Carolina, Virginia, Tennessee, Maine, most of Iowa, Chicago and parts of Oklahoma.
If you’re a road warrior, shop elsewhere.
The US Cellular coverage map for 3G is very specific (read: regional). Be sure check if you’ve got coverage where you live and where you go before picking it up
You’ll need the kind of reliable coverage Verizon or Sprint can offer (AT&T’s network is too burdened by the iPhone).
However, if you’re mostly stationary or just travel within one city or two, then it might be possible to cash in on the savings US Cellular plans provide ($10 less than most carriers).
Rather than list a bunch of cities that constantly change, it just makes sense to use the US Cellular 3G coverage map to figure out if you’re covered.
You can find it below (or here if it’s not loading). Be sure to click on “Data Coverage” to see 3G coverage highlighted in green: