Instead of sending a cheque to the mosque or the orphanage can we perhaps take the time to help in the administration of the mosque, in its maintanence, spending a day with the orphans, helping out or even voluntarily teaching at religious schools. Most of all, Allah will look upon you fondly, Inshallah, for prolonging the life of a fellow human being. Giving a second chance at life to a person could mean so many things. Everyone deserves a second chance and it's so easy for you to give this gift. So very few Muslims in Singapore perform life giving deeds.
Blood donation is completely halal because it harms neither they donor nor the receipient.
Before blood donation, your Blood pressure is measured and blood tests done to evaluate the hemoglobin, hematocrit etc. Drawing this amount of blood is not dangerous for a healthy person. After this procedure, you can rest for a while to stimulate and equilibrate your blood circulation. Use of sterile, disposable needles and plastic bags, used once and then discarded, along with other required precastionary measures. Another special way to save a life is by registering yourself as a bone-marrow donor.