Amazon Wallet is just the latest service looking to help you pay for things on the go. But where does it fit in with the other major players looking to manage your digital wallet?
Google's Wallet service has arrived on iOS with a native app that is well-designed, but ultimately only mildly useful.
Google is integrating Gmail with Google Wallet so that users can send payments as a mail attachment, even if the recipient doesn't have a Gmail address.
A new version of Google Wallet is in the works and while few details about it are available, it appears that it will support multiple phone operating systems.