Savers can now buy the Treasury’s popular I bonds online with automatic payments from their checking accounts. The bonds, in denominations as low as $25, are posted electronically at Treasurydirect.gov, where savers can check their earnings at any time. Granted, the returns aren’t eyepopping: these bonds are currently paying 2.57 percent. But the rates are guaranteed to rise with inflation, and there’s nothing safer than a Treasury bond, even if it’s never put on paper. Gift givers who want the actual certificates can still buy them at banks or online with a credit card.