[nradov]

That's not quite accurate. Charitable donations are (generally) deductible on income tax returns. But tax brackets apply at marginal levels. There is no way to actually "save" money by donating to charity. The only exception is if you donate goods and then cheat by valuing those goods at above the market rate; some charities used to facilitate this by giving out receipts for inflated values but the IRS has been cracking down on that.