HT from Mars Blog.
Mars is retrograding (moving westward) through the stars of Gemini and will cross over into Taurus on Dec. 30. It will come closest to the Earth on the night of Dec. 18 (around 6:46 p.m. EST). The planet is then 54,783,381 miles (88,165,305 kilometers) from Earth. It is at opposition – exactly opposite from the sun, with Earth in the middle – six days later, on Christmas Eve, Dec. 24.
It will then gleam at magnitude -1.6, and through Jan. 2, 2008, will outshine Sirius, the brightest star.
The night that Mars will probably attract the most attention, from even those who don't normally look up at the sky, will be on the night before Christmas Eve: Sunday, Dec. 23. That will be the night of a full moon, and Mars will serve as a companion to it all through that night. In fact, it will result in an exceptionally close approach between the two across much of the United States, while for parts of the Pacific Northwest, southern and western Canada and Europe, the moon will actually occult (hide) Mars.
From Space.com here.