Firefox: Snoozing emails is a pretty common practice these days, so it makes sense to bring that same feature to your browser. Chrome has the Tab Snooze extension, and Firefox users can get it using Firefox's own Test Pilot extension.
The Test Pilot extension is packed with all kinds of experimental features, including a mini video players, a bizarre tab sidebar, a screenshot tool, and now, a tab snoozing kit. To take it for a test drive, just head to Firefox's Test Pilot site and add it into Firefox. Once it's set up, you can snooze tabs for various time periods, and that tab will then temporarily disappear until you need them.
Snooze Tabs [Firefox Test Pilot]