Google Chrome has nifty features, ofcourse Firefox is more customizable than Chrome. One of the useful feature of Google Chrome is the new tab feature, when you open a new tab on Chrome it shows 9 most visited sites thumbnails, you can click those thumbnails to get to those site quickly. The new updated Google toolbar gives Firefox this new tab feature.
Once installed when you open a new tab in Firefox it shows the thumbnail view of the favorite sites you visit, recent bookmarks and recently closed tabs similar to Google chrome. All this data resides on your local computer, and it won’t send to Google.
This toolbar isn’t compatible with Firefox 2 and some tab extensions may conflict with this add-on according to Google Blog