The National Kidney Registry called it "Chain 124." It began last August and lasted through December, linking 60 lives forever in the longest-ever chain of kidney transplants.  Through the cooperation of seventeen hospitals in eleven states, it connected 30 people who needed a kidney with 30 people willing to give up an organ to a complete stranger. Transplant chains like this are rare, but computer models suggest thousands more transplants could be made each year if there were a national databank of willing donors and recipients — and if more Americans knew about such programs.