Rated 5 out of 5 stars
I frankly thought it was going to be useless until I tried it. It is really good and I feel that I will get used to having a vertical bar and leave room for showing the URL and also have less clutter on the top, where I always look for controls I commonly use.
I wish Mozilla can incorporate something like this in Firefox and add more functionality to it. This is way better than the new Firefox 4 menu.