Remember when Clearwire promised they'd bring WiMax to 80 cities within 18 months? Well, they've started with Las Vegas, Portland and Atlanta (the latter being right in AT&T's backyard), and Sprint is set to take advantage.

Sprint, which owns a 51% stake in Clearwire, says it will offer 10Mbps download and 3-6Mbps upload speeds in those three cities, which is a pretty sweet deal for Sprint customers. Now come on, Clearwire: make good on your promise and blanket the country with sweet 4G action. [mocoNews]