If you ever want to divide your open Chrome tabs into multiple browser windows, nothing makes it easier than Tab Scissors.
The extension couldn't be simpler. All you have to do is select a tab in Chrome, click the extension icon and your browser window will instantly split in two. Any tabs that were to the left of your active tab will be transferred to the left window, and the rest will be on the right.
While you might not need to use it often, it's great if you want to bookmark a handful of tabs at once without closing the rest, or for splitting your browser into distinct windows for fun distractions and work-related web pages.