President Bush praised U.S. troops on Saturday and gave a special thank-you to military families who have turned the grief of losing loved ones into acts of compassion.

For many relatives of U.S. troops, military service means packing up their belongings and moving on short notice, living in a foreign country or missing a family member as he or she serves overseas, Bush said in his weekly radio address.

Bush taped his broadcast on Friday before leaving aboard the Marine One presidential helicopter to fly to Camp David with first lady Laura Bush; their daughter Jenna; and Mrs. Bush's mother, Jenna Welch. He will celebrate Christmas with his family at the presidential retreat in Maryland's Catoctin Mountains, then travel to his Texas ranch the day after Christmas.

"This Christmas, many will sit down for dinner thinking of their loved ones half a world away," Bush said. "These families deserve the thanks and the prayers of our whole nation."

Bush said Army Spc. Michael Rodriguez of Knoxville, Tenn., often wrote to his family about children he met on patrol during his deployment in Iraq. Rodriguez was killed in April by a suicide bomber, but his family honors his memory by helping collect school supplies for students at an Iraqi school for girls.

Last year, Kirsten Yuhl-Torres of San Diego, Calif., lost her son, Sgt. Joseph Perry, in Iraq.

"To honor Joseph's memory," Bush said, "she started sending care packages and writing letters of support to other soldiers serving there. Kirsten says, 'Joe was our only son, but now we have hundreds."'

The president also told the story of Bob Lehmiller, whose son, Sgt. Mike Lehmiller, was killed in 2005 while serving in Afghanistan. To honor his son, Lehmiller created Mike's Guardian Eagle Foundation, which assists military families that need extra help when their loved ones are deployed, or when they're wounded or killed on the battlefield.

"All these families have already given so much to America, and yet they have found a way to give even more," the president said. "We thank each of them, and we thank every one of our citizens who supports our troops with letters and donations or prayers."