The shared intellectual space inhabited by bloggers (people who blog). It is actually more than the space, it is the community of bloggers itself and their collective voice. Blogs are increasing in popularity as a way for people to self-publish their insights on the Web and because of the free nature of this expression, they are transforming the way people and journalists work together to report, filter and break the news. One example of its usage is, "Reaction was swift in the blogosphere."
Because the term combines blog and biosphere, "blogosphere" captures the essense of Web logs as part of the media ecosystem. A second example of its usage is, "I've seen that link bouncing around the blogosphere lately." And a third usage example is, "It's hard to imagine working mothers making time to surf the blogosphere after work."
FYI: As of April 2006, the blogosphere is doubling in size every 6 months and is now over 60 times bigger than it was 3 years prior. On average, a new weblog is created every second of every day, and the popular blog "Technorati" tracks about 1.2 million new blog posts each day (that's about 50,000 per hour).