Time Warner Cable has started offering 3G/4G hotspots to customers in selected areas…and Clearwire is taking the devices nationwide.

Wireless operator Sprint has been making much ado over its 4G WiMax network, which is lighting up in a growing number of major markets around the United States—although places like New York, L.A., San Francisco, Washington D.C., and Boston are still waiting. Part of its strategy has been selling 3G/4G combination hotspots that enable users to tap into mobile Internet capabilities using Wi-Fi devices. For the last few months, Sprint’s offering has been the Sierra Wireless AirCard W801 Mobile Hotspot rebranded as the “Overdrive,” with Clearannouncing a rebranded version of the same device dubbed the “Spot.” Today there are two new developments: Clear is announcing nationwide availability of its hotspots , and Sprint partner Time Warner Cable has announced plans to offer the device to Road Runner Mobile customers.

Time Warner is rebranding its version of the Sierra Wireless AirCard W801 Mobile Hotspot as the IntelliGo; like the other 3G/4G hotspot offerings, it enables users to connect up to five WiFi-enabled devices to the Internet using either 3G or WiMax technology, whatever is available in a particular service area. The IntelliGo will be available to Road Runner Mobile customers in selected markets, starting out in portions of Texas, North Carolina, Hawaii, and Missouri, although customers will be able to tap into 4G WiMax connectivity in other markets where it’s available. The service will run $49.99 a month with a two-year service plan.

Clear, meanwhile has announced it’s now offering its Clear Spot 4G and 4G+ devices nationwide in Clear retail stores as well as through authorized dealers. Announced just a few weeks ago, the Clear Spots 4G+ should have familiar specs: it enables up to 5 Wi-Fi devices to connect to the Internet, and drops down to 3G coverage in areas where WiMax isn’t available. Clear will also offer a WiMax-only version for non-roaming types, and a 3G/4G USB modem. The 4G+ version costs $224.99 or can be leased for $5.99 a month; monthly service plans start at $55 per month. The 4G-only version runs $99.99 (or a $4.99/month lease) and plans start at $40/month.