Google Chrome adds option to hide any extension's button
Just right-click the icon you want to disappear and select hide button, and it's gone. If you should happen to get removal remorse, just head to chrome://extensions and you'll find a show button link next to any extension you've previously hidden.
Yes, you could already drag-to-resize the entire browser actions area to hide any buttons which happened to be on the right-hand side -- but now you've got full control over which extensions get space on your toolbar and which don't.
At last, extensions which you can call from the context menu or invoke with a hotkey don't have to chew up valuable toolbar real estate in Google Chrome.