TEMPE, Ariz.  For a homeless man like Dave Tally, the $3,300 in cash that he found in an abandoned backpack a few weeks ago would have gone a long way. Food. Shelter. Repairs to his bicycle. Spending it would not have been a problem.

But Mr. Tally, who is recovering from drug and alcohol addictions, transformed his life in a different way: by turning the money in.

He gave the backpack to the Tempe Community Action Agency, the social service organization where he volunteers, whose officials managed to trace it to Bryan Belanger, an Arizona State University student who lost the money while on his way to buy a used car.

In news accounts, Mr. Tally has been praised as a homeless hero. People moved by his selflessness have sent him checks  totaling far more than was in the backpack  and have offered him jobs to help him get on his feet.