If you've grown very, very tired of having to manually select the next message to view in Gmail after archiving, deleting, muting or otherwise handling a message, your conveyor belt has arrived. A new Labs feature, Auto-advance, speeds you through your inbox.
Gmail's team notes that "keyboard ninjas will already be familiar with the "] " and "[" keyboard shortcuts for archiving and going to the next/previous conversation" — well, not all of us, actually (ahem). To set up Auto-advance, head into your Labs settings, search for and enable "Auto-advance," save your changes on that page, then head into your General section of Settings. You'll see a new Auto-advance section, where you can choose what happens when you're tapping through your emails, whether being sent to a newer or older message, or right back to the inbox, per usual.
New in Labs: Auto-advance to the next conversation [Official Gmail Blog]