1 Photo - Feb 14, 2013
Photo: Here's something really cool about the new Message Center hidden behind the flag "Enable Rich Notifications" in chrome://flags.

There is a Quiet Mode. You can tune it for one hour, one day or turn it off. Therefore, there won't be any popups (especially useful during presentations). Don't worry, notifications will be stored in the Message Center for later.

This only works for Chrome OS and Windows for now.

Source: http://codereview.chromium.org/12221027/