I stumbled upon ( just love this proverb ) this nice article about different types of review techniques for software developing or engineering teams. Definitely worth reading.

Edit: I'm forced to claim that with appropriate code reviewing, the already world-famous bug in Microsoft's Zune would have been found, prior to causing many people so much trouble. Look and Learn..

year = ORIGINYEAR; /* = 1980 */

while (days > 365)
{
    if (IsLeapYear(year))
    {
        if (days > 366)
        {
            days -= 366;
            year += 1;
        }
    }
    else
    {
        days -= 365;
        year += 1;
    }
}

If you don't get it at the first sight: http://www.crunchgear.com/2008/12/31/zune-bug-explained-in-detail/ should help.