Starting today, you can pay for items at a variety of online stores using your Amazon.com account. The retailer has announced a new "Login and Pay with Amazon" program that it says "streamlines how customers transact with online merchants." With more than 215 million active customer accounts under its belt, Amazon apparently thinks now is the time to make its most aggressive push yet in challenging PayPal and other online payment services. Using its widgets and APIs, Amazon says online vendors can now "replace guest checkouts with recognized customers," which will help retailers track orders, purchase history, offer special discounts, and more.

For consumers, it means avoiding the hassle of signing up for dedicated accounts at every web store they buy from. Instead, you'll only need to remember your Amazon login — assuming the new payment method can pick up traction. Integrating Login and Pay with Amazon isn't free for businesses; Amazon collects a fee for each transaction it processes, but there's no monthly fee involved, and participants also receive free fraud protection. At launch, partners including Gogo, Ace Hardware, Brookstone, J&R Electronics, Lenovo, OWC, and Petco, among others.