I just discovered that Gmail's "Select All … Conversations in Inbox feature has disappeared, leaving users with no clear way to apply an action to their entire inbox. Sure, you could hit the little checkbox to "select all," but it really only selects 50 messages at a time, which is useless when you're dealing with 10,000+ Facebook updates. Fortunately, there's a work-around.

To archive all the emails in your Gmail inbox:

1. Enter in:inbox into the search bar
2. Press the search button or press return to run the search
3. Click on the small down arrow on the search bar and select Create filter with this search
4. Click OK when warned that the filter will not apply to new mail
5. Select Skip the Inbox (Archive It) and Also apply filter to X matching conversations.
6. Click Create Filter

Gmail will think for a moment, then poof! your inbox will be empty, with all your mail tucked away safely in your archive. It's a good idea to delete the filter you just created to avoid unwanted behavior. Just navigate Settings --> Filter and delete the in:Inbox filter.

The great thing about this method is that it depends entirely on Gmail's filtering feature with no reliance on specific user interface features. That means it will keep working even when they break Compose again. It also means that you can use this method to bulk-process your email with any rules supported by filters. For example, you could mark everything as read by creating a filter for is:unread and applying the filter action mark as read.

Now sit back and enjoy the psychological breathing room of inbox zero / email bankruptcy !