New version of Google Wallet supports all credit and debit cards in the US.
Now you can use Visa, MasterCard, American Express, and Discover when you shop in-store or online with Google Wallet. If you already have an online Google Wallet account, your cards will be automatically synced to your Google Wallet app.
A new security feature in the new version lets you remotely disable your mobile wallet app from your Google Wallet account on the web, In case you ever lose your phone.
Download from Google Play: http://goo.gl/4HFC6