Be aware that Mars' gravity is only .37 that of Earth's, meaning that a 3 pound weight will feel like 1 pound.  This may seem exciting, but remember that it still has the same MASS.  Meaning that while it will take a little less time to fall, it will still hit you in the chest with the same oomph as a 3 pound weight.  So if you throw a 30 pound box weighing only 10 pounds, it'll still hit with 30 pounds.  So be careful!