This battlefield bandage is made of chitosan, a substance derived from the shells of shrimp. Chitosan carries a positive ionic charge, so it attracts blood, which has a negative ionic charge; the result is that the bandage--which can last for up to 48 hours--seals a wound with a tight blood-clot formation. Because HemCon's bandages are suitable for treating gunshots and other irregular wounds, the Army now issues them to every soldier who faces a combat situation. Bandages sold in 2006: 270,000. Price: Between $10 and $150, depending on the size of the bandage.