(MONEY Magazine) – September's "How to Slash College Costs" overlooked one method: If you join the military for two or more years, you can get financial help through the G.I. Bill when you enroll in college after discharge. The military will also pay for college courses you take in the evenings while you're in service. After three years in the Marine Corps, I enrolled at a four-year public college, San Diego State University, and was granted 24 semester credits for work done in the military. This put me only six credits short of a full year toward graduation. With the head start and by taking summer classes, I earned a four-year degree in 2 1/2 years. Robert E. Perry El Cajon, Calif.