I felt very privileged to take part in bonn katin in Battambang with my mother last month. October is the month in which people make offerings to the temple. Since bonn katin involve a sizable donation (often several thousands of dollars) to the temple, it is a once-in-a-lifetime event that brings a lot of joy and bonn to the benefactor.
Cambodia is about 90-95% Buddhist, so you hear the word bonn being tossed around a lot. People "tver bonn" by giving to beggars and charities or by doing favors for others.
However, there seems to be some confusion as to what the word bonn really means. When people tver bonn, they usually expect something in return. Since many Buddhists believe in reincarnation, they usually expect their good deeds to reward them with a more favorable rebirth.
Although I'm not a Buddhist scholar, I don't think this the right way to look at bonn. Bonn is not a concept that can be described easily in words and is perhaps best understood in the meditative state. When I think of bonn, I think of benevolence, compassion, equanimity, and mutual prosperity for the present moment. Bonn is good deeds performed for the sake of goodness.
Bonn is present only when the benefactor does it without expecting anything in return. If I donate $1,000 to a temple and become upset if my name isn't announced to the crowd or scribed on a big poster, then I'm really not tver bonn; I'm just seeking attention and making a name for myself.
Bonn is an act of true compassion and selflessness that holds to the highest esteem the virtues of balance and mutual benevolence. It is an this unconditional goodness that inspires and brings out the best of everyone-- in the present moment, not in a future life.
If one does a good deed in hopes of being reborn into wealth rather than poverty, then it's really not bonn. The deed, however noble, is not done solely for collective benefit. It is, rather, a selfish and calculated move to profit in a future life. Deep down he or she really accepts and even espouses the injustices and disparities that exist in the world and wishes to end up on the favorable side of the imbalance.
I think random acts of kindness are the highest expression of bonn.