Chrome was the browser with the most new users in June 2011, according to stats released from w3school.com. Their 2% gain came mostly from Internet Explorer's lost users. Most other browsers remained fairly constant. Here is the breakdown, with a comparison to May.

June 2011
I.E. 23.2 %
Firefox 42.2 %
Chrome 27.9 %
Safari 3.7 %
Opera 2.4 %

May 2011
I.E. 24.9 %
Firefox 42.4 %
Chrome 25.9 %
Safari 4.0 %
Opera 2.4 %