The June 2009 Social Radar Top 50 measures the brands with the most active Web presence based on overall online conversation volume. To create the Top 50 list, we used Social Radar to analyze millions of blog posts, news feeds, forums, social networks and Twitter posts to aggregate a list of the words and brands mentioned most frequently on the Web during June 2009. The list measures the number of unique individuals or sources that posted content about each brand during May 2009 rather than the overall number of mentions, which would be more heavily influenced by big fans who post frequently about a specific brand.

Twitter held on to the top spot, though once again trending down this month. iPhone jumped two spots to #2 overall and Apple jumped three spots to #6 thanks to buzz around the iPhone 3G S release.

Firefox jumped 10 spots thanks to increased chatter leading up to its new Firefox 3.5 release, which was downloaded more than a million times within a few hours.

XBox jumped 5 spots to #11 overall after the Project Natal announcement at Electronic Entertainment Expo (E3). Surprisingly, with both the Project Natal and Bing search engine announcements this month, overall Microsoft buzz only increased one spot to #9 overall.

CNN jumped 13 spots, due in large part to a steep surge surrouding the news of Michael Jackson’s death. MLB jumped eight spots as the baseball season heated up in the month of June.

Finally, HTC joined the Top 50 this month, with talk about its new widget-based HTC Hero Android smartphone announcement.

View the full list below, or download the PDF. For additional information about how you can analyze chatter sentiment to gauge positivity/negativity, view key words mentioned about your brand and identify key influencers, visit www.infegy.com/socialradar.

Questions or comments? Twitter me @adamcoomes.