Fred Hatfield know as Dr. Squat has a neat little protein requirements guide on his site along with his Power Protein Plus.
ESTIMATE PROCEDURE FOR DETERMINING APPROXIMATE DAILY PROTEIN REQUIREMENTS
Lean Bodyweight (in pounds) x Requirement Factor = Daily Protein Requirement (in grams)
Requirement Factors:
.5 - Sedentary, no sports or training
.6 - Jogger or light fitness training
.7 - Sports participation or moderate training 3X week
.8 - Moderate daily weight training or aerobic training
.9 - Heavy weight training daily
1.0 - Heavy weight training daily plus sports training,or "two-a day" training