The Guardian reports on a new Nielsen Online report Global Faces and Networked Places (PDF) that says blogs and social networking sites are now “the fourth most popular category online – ahead of personal email.”

Two thirds of us now use “member communities” — and their popularity is being boosted by the growing use of mobiles for internet access.

Use of these tools is highest in Brazil:

Among the markets Nielsen measured, penetration of visits to social networks and blogs was highest in Brazil, where 80% of the online audience visits such sites. The share of overall Internet time for which social networks and blogs account is also highest in Brazil, where nearly one in four (23%) of minutes spent online is spent on these sites.

The UK and US aren’t far behind – 69% of the online audience in the UK, and 67% in the US visit blogs and social networks, but the growth rate is quite different. Between 2007 and 2008, usage grew by 10.3% in the UK, but only 2.9% in the US.

Via /Messagelinks.