Here is the browser market share for September 2007, based on traffic to my top site:
Firefox had a strong September, gaining 0.88% during the month. Much of the increase came at the expense of IE, which saw a drop of 0.92% in September. The smaller browsers did not see much change. In fact, the Firefox share number is the highest since I started reporting browser market share a year ago. Given that September is the back-to-school month, this could signify that Firefox is gaining usage among students.