Is it REALLY possible to improve a 'bad' singing voice? If so, what's the best way to do so?

If you want to get better all i can say is sing. Sing all the time! Try some vocal excercises and see what you can do. Try singing in different pitches and sing songs for your area. Soprano, alto,barratone, tennor, sometimes youd be surprised. Maybe even try working w/ a vocal coach.