Google Spreadsheets invites using chat feature

I signed up for an invitation to the new Google Spreadsheets beta, and it only took about a day for the invite to arrive. I played around with it, saw some cool features, but wanted to show my friend what it was like. I couldn’t see any “Invite” button or functionality in the application, but I did see a “Share this Spreadsheet” link at the top-right.

Clicking the link opens an invitation sidebar that allows you to invite others to read or edit the document:

You can only invite users who have Google Accounts, but hey: who doesn’t have one by now? As soon as the invited user opens the spreadsheet, the sharing section changes:

Clicking “Chat with …” displays a sidebar allowing the spreadsheet’s users to chat while editing the spreadsheet, all in real-time.

Keep up the suprises, Google