Last year, the time Americans spent social networking grew 277%, Twitter grew 500%, and the average US worker spends five hours a moth visiting social network sites at the office. Oh yeah, and Facebook is the No. 3 site for Americans 65 and older (smart grandparents). All this is according to Nielsen's Fact Sheet 2010. As for general Internet use (not just the social part), Nielsen says there are about 195 million active users in the US, 160.3 million of them broadband users. It says broadband penetration was 93.3% at the end of last year, up 16% from 2008. Pew/Internet, however, just released some more conservative numbers showing that "74% of American adults (ages 18 and older) use the Internet – a slight drop from our survey in April 2009, which did not include Spanish interviews. The breakdowns for Net use by age and ethnicity, respectively, are: 18-29 (93%); 30-49 (81%); 50-64 (70%); and 65+ (38%); and white, non-Hispanic (76%); black, non-Hispanic (59%); and Hispanic, English- and Spanish-speaking (55%). Pew also found that household broadband penetration is at 60%, "a drop that is within the margin of error from 63% in April 2009," and that "55% of American adults connect to the internet wirelessly, either through a WiFi or WiMax connection via their laptops or through their handheld device like a smart phone."