Desert Blood Services will conduct two community blood drives tomorrow. Residents may donate blood at High Desert Medical Center in Joshua Tree from 10 to 2, or at the Yucca Valley Community Center from noon to 4. Donors will receive incentives. In addition, Desert Blood Services now offers donors free cholesterol screening with every blood donation. All prospective donors should be free of infections or illness, weigh at least 110 pounds, and not be at risk for AIDS or hepatitis. To make an appointment to donate blood, call 877-827-4376.