The researchers conducted the study by giving each volunteer a beeper that went off every two hours or so.

ECONOMIST: Human evolution

There was a principals committee meeting that lasted two hours or so in the Situation Room earlier today that ended not that long ago -- again, one of the reasons why I wanted to wait for that to end before I came out here.

WHITEHOUSE: Press Briefing

Rory claims he became confused over time zones and said it was a State Trooper in an unmarked car who helped him arrive at the course with 10-11 minutes to spare (as opposed to the usual two hours or so pro players usually allot).

FORBES: 10 Reasons Why The U.S. Lost The Ryder Cup

I'm training six days a week for two hours or more, so I'm doing all I can (to get to the 2016 Paralympics) and my heart's there.

CNN: Teen beating the odds after brain injury

Brad Setser, of Roubini Global Economics, an economic-analysis website, is paid to spend two to three hours or so each day blogging as a part of his job.

ECONOMIST: Why do economists spend valuable time blogging?

Each night, they spent two hours preparing a dozen or so rods, checking knots, sharpening and baiting hooks for the next day.

WSJ: A College Championship That's a Different Kettle of Fish

Make regular stops -- every two hours for a puppy, every three to four hours for a cat or an adult dog -- so your pet can take a walk on a leash (some cats enjoy a little leash walk).

CNN: Tips for road tripping with pets

Topsy lets you slice the results by time, so by the last hour, two hours, or day (and further).

FORBES: Topsy Takes On Google In Timely Searches

The 12 or so participants talked about the Levy case in depth for two hours.

CNN: Director's log: Sheryl McCollum