"One who saves a single life - it is as if he has saved an entire world"
Pirke D'Rav Eliezer, Chapter 48
It is DoNation week on the BBC. People are encouraged to sign up for the National Donor Register that keeps track of those who would like to donate their organs after their death.
It takes 30 seconds to sign up for this register. Even if you carry a UK donor card it makes sense to sign up as hoispitals can simply download the data fomr this list if they can not find a donor card on somebody's personal belongings. If you think you are already registered but you are not sure: Register again as the system will update your current information.
If you would like to receive organs if you ever become ill, you have no choice but to sign yourself up in case someone else needs your organs after you die. If you take, you MUST be prepared to give.