A money savvy Marine Corps sergeant serving in Iraq didn't wait to get back home to buy a shiny new car with his $30,000 re- enlistment bonus. Instead, he invested all of it into the Thrift Savings Plan. "Assuming a 7 percent rate of return, his $30,000 is projected to be $345,000 by the time he reaches age 60," said Army Lt. Col. Janet Fenton, executive director of Armed Forces Tax Council. "If he continues to contribute to TSP throughout his career, he could have more than $1 million saved by the time he retires." A million dollars isn't anything...