Everyday, Gmail makes desktop mail clients feel a little more dated. The latest Labs features now preview stuff from YouTube (no more Rickrolling??), Flickr, Picasa and Yelp, and you can undo sending regrettable email.
https://lifehacker.com/gmail-goes-offline-with-google-gears-5140668
Undo send, sadly, only has a five-second window to take it back (you can boost it to 10), so you better have excellent reflexes. Previews work a lot like the image preview you’re used to. Here’s the YouTube preview in action:
[Gmail Blog, Cnet]
