There is a full-size statue of the Buddha in my neighborhood. Sometimes when I walk by I leave some coins at His feet. I think of it as an offering. But also I think of it as for anyone to take who needs the money. There are a few beggers in the neighborhood, so I consider it an offering to the needy as well. But it just struck me: am I contributing to someone's negative karma by giving them the temptation to take offerings left at the feet of the Buddha? Would I be doing a better service to give money directly to the beggers, and make offerings to the Buddha of flowers or something that would not be so tempting?

I think you're probably right that giving the money directly to beggers would be a better idea in order to avoid someone collecting negative karma by taking it from the foot of the statue. Although from your side, you were giving it to the hypothetical beggers willingly, from their side, they're taking it. I also agree that something less tempting like flowers would be great!