Google tacked another announcement onto a day full of them with an update to Google Wallet that lets you send money via Gmail.
As the video above explains there will be a dollar-sign icon for Gmail attachments. Click it and you can transfer cash via Google Wallet. The recipient doesn't have to have a Gmail address and you can receive money as well. You can also pay using your credit and debit cards for a fee of 2.9% per transaction (minimum $0.30.)
Google claims the transactions are encrypted and stored on secure servers. Transactions are also monitored to preempt fraudulent activity. Google Wallet Purchase Protection also covers 100% of "eligible unauthorized transactions."
Introduced in 2011, Google Wallet has not yet gone mainstream, in part because of consumer resistance to mobile-based transactions, but also because of a lack of awareness and retail deployment. As with Google+ though, Google is using its huge Gmail footprint to help further the technology's acceptance.