Windows/Mac/Linux (Chrome): It's okay to fit a little social networking and not-quite-job-related news reading into your day, but mental limits are hard to stick to. StayFocusd sets timers on the sites you know are addictive, then blocks them when time's up.

Rather than set individual time limits for each site, StayFocusd asks for a total amount of time you want to let yourself spend on all your non-productive sites. Kind of a clever restriction to have, because you just know you'd be heading right over to Twitter once your Facebook timer ran out, and vice-versa. StayFocusd does get specific on site URLs, though. You can timer-block the entirety of Reddit, for example, but leave the link submission section open for use throughout the day.

StayFocusd is a free download, works wherever Chrome Extensions do. For a similar strategy of blocking and controlling time-sink sites on Firefox, check out our guide to saving yourself with LeechBlock.