The Gmail team has done it again, and they’ve given Gmail users a whole slew of cool new features.

We’ve now got YouTube, Picasa and Flickr previews, built right into each email message. All we have to do is to put a link to a YouTube movie, or a Picasa or Flickr photo, and its thumbnail shows directly in the message. This feature can be enabled by service from the Labs settings in our Gmail accounts.

I love the “Undo send” feature and have already enabled it. My wife is already using the Offline version of email. It took a bit to sync all her messages, but it’s doing alright now.

Other Gmail features I love are as follows:

• Superstars, which adds additional stars icons. I organize emails that I need to act on that way.
• Signature tweaks, which places the signature above quoted text
• Right-side labels
• Navbar drag-and-drop, which allows me to re-organize the various items on the Gmail screen
• Forgotten attachment detector
• Vacation Time, which lets me specify beginning and ending dates for those times when I can’t get to my email
• Create a Document, which allows me to create a Google Document right from my Gmail inbox (this is new)
• Send & Archive, which allows me to reply and archive that message at the same time (this is new)
• Title Tweaks, which changes the order of the text in the Gmail page title, allowing me to see right away how many unread messages there are (this is new)
• Google Docs gadget, which displays my most recent Google Documents on my Gmail inbox screen

There’s more information about the new features on the Gmail Blog, here and here.