The network will triple its coverage area this month, and he predicts Tesla owners will be able to drive from LA to NY using only Superchargers by the end of 2013.

ENGADGET

Verizon Wireless' 4G LTE Mobile Broadband network currently reaches one-third of all Americans, with plans to expand the network to the company's entire 3G coverage area over the next three years.

ENGADGET: Panasonic and Verizon team up to Mobile HD Visual Communications System using LTE

Nielsen's survey didn't find a dominant social class on Twitter as much as they found a geographical one: Those who use Twitter are more likely to live in an urban area where there's greater access to wireless network coverage, Mancini said.

CNN: Does class decide online social networks?

With other carriers, when you travel outside of their LTE coverage area, you may be on a much slower 3G network.

ENGADGET: AT&T 4G LTE adds Galaxy Note II, Galaxy Tab 2 10.1, Galaxy Express and Galaxy Rugby Pro to lineup

With smartphones on other carriers' networks, when you travel outside of their LTE coverage area, you may be on a much slower 3G network.

ENGADGET: Nokia Lumia 920 and 820 land stateside on AT&T's 4G LTE network this November

O2 Wifi is free for everyone, regardless of network or broadband provider and once registered, customers will be automatically connected each time they enter a coverage area.

ENGADGET: O2 offering free WiFi around London's busiest streets