Chrome: This might be the quickest way to share links with others. Just click the Send from Gmail (by Google) button and a new email message is prepped for you with the web page title as the subject line and the link in the body. All you have to do is enter your recipient and click send.
The extension works with Google Apps and you can customise the message to have a prefix in the subject field. For example: "Interesting link:"
Also, since it's one click from the toolbar to creating a new email message from any page, you can use this to quickly send any kind of email — you just have to edit the title and body.
This extension has been around for a while, but it was new to us. Hopefully all you frequent link-sharers will enjoy it.