Amid all the hubbub of its I/O developer conference, Google has found time to teach Gmail some new tricks with the introduction of quick action buttons that will let you act on emails without even opening them. The buttons appear next to certain types of messages, so if someone sends you a calendar invite, for example, a button will show up on top of the email line that lets you RSVP or decline the invitation.

Reviewing goods, movies, restaurants and services is another common action that can be performed directly from the inbox, according to Google. Other supported actions include one-click replies for tasks like confirming registration emails, and linking to airport check-in sites when receiving flight confirmation details.

Speaking of flight confirmation emails, Google is also introducing interactive cards that display all the important information at the top of emails, so you can check whether your flight and connections are on time at a glance.

The new quick action buttons will roll out over the next few weeks to all Gmail users. The company is calling on developers and companies to create their own quick actions, with initial partners already including big names like Spotify (to play songs mentioned or linked to in emails) as well as Netflix.

In somewhat related news, Google recently announced another noteworthy addition to Gmail that taps into the company's Wallet service to allow sending money via attachments. A dollar-sign icon will be added to the row of options in the compose window, and those who have linked Google Wallet to their bank account or who have Google Wallet balance can send money to their contacts by clicking on it.

Recipients don't have to be on Gmail, but they do need to have a Google Wallet account. Transferring money is free when the funds come from a linked bank account or a user's Google Wallet balance, but those who use a linked debit or credit card must pay a flat fee of 2.9 percent or $0.30 minimum per transaction. There's also a $10,000 per transaction and $50,000 over a five-day period limitation for the service.