Tonight, midnight arrives one second later. I just read in CNN.com and BBC News that a leap second will be added to 2008 to adjust the atomic clocks. Apparently, the earth's daily rotation is not always exactly 24 hours. Disruptions to the earth's core, extreme weather, volcanic eruptions as well as earthquakes can influence the length of a day. Since 1972, there have been 23 leap seconds added.
Happy New Year!