In an effort to simplify e-commerce and increase the appeal of its online payment platform to merchants, Amazon Payments, a subsidiary of Amazon.com, on Thursday announced the availability of PayPhrase, a way for online shoppers to authorize purchases without entering a username and password.

PayPhrase lets online shoppers complete the online checkout process using their Amazon preferred payment and shipping settings without sharing payment information across multiple Web sites.

"PayPhrase solves the headache of trying to keep track of all the different usernames and passwords people use to shop on various sites across the Web," said Amazon PayPhrase general manger Matt Williams in a statement. "With PayPhrase, all you need is one phrase and one PIN to pay online."

Using a customized phrase, such as "Stop Me Before I Shop Again" or "Get Ready For My Customer Support Call," consumers at Amazon.com or at other Web sites that accept PayPhrase can quickly preview purchases and authorize them with a four-digit PIN.

PayPhrase is less fun than it might be due to Amazon's content restrictions.

PayPhrases can't use trademarked terms. Nor can they use language that is "unlawful, libelous, defamatory, obscene, pornographic, indecent, lewd, harassing, threatening, harmful, invasive of privacy or publicity rights, abusive, inflammatory, or otherwise objectionable..."

A PayPhrase must be at least two words, at least four characters, and cannot exceed 100 characters. No special characters or numbers are allowed.

PayPhrase also cannot be used to purchase digital goods, like MP3 downloads.

Nonetheless, PayPhrase should find enthusiastic use among parents with dependents who need to shop online: PayPhrases and PINs can be shared with family members (or anyone for that matter), enabling them to make online purchases that are subject to a pre-set spending limit and an optional approval process.

Amazon Payments competes with PayPal, Google Checkout, and bank payment platforms. Merchants planning to offer PayPhrase include DKNY, Jockey, Patagonia, Buy.com, J&R Electronics, and Car Toys.