Military members who perform TDY (Temporary Duty) away from their normal duty stations are authorized to be reimbursed for additional expenses, such as lodging and meals. The military reimburses such expenses in the way of a daily "Per Diem" payment. The maximum amount of Per Diem differs from one location to another, depending on the "cost of living" of that area.
The below links provide the CONUS (Continental United States) Per Diem rates for Fiscal Year 2008: The rates are effective from October 1, 2007 to September 30, 2008.
For Alaska and Hawaii, see Overseas Per Diem Rates.