Australia - Facebook key driver in Australians' uptake of social media.

Nearly four in five (78%) of Australia's nine million internet users sent or shared a photo in the past year and nearly three quarters (74%) sent or shared a link. The biggest increases in social media usage were reading and posting on Twitter, reading wikis and engaging with brands and organisations via social media, according to Nielsen. Twitter's audience levels grew by more than 400 percent in 2009 and nearly one quarter of online Australians (23%) read 'tweets' in the past year, 14 percent 'followed' companies or organisations via Twitter (up from 5% in 2008) and 13 percent posted 'tweets' (up from 4% in 2008). Wikis continued to grow as a popular form of online content - close to …