Amazon announced the new button yesterday, and the Washington Post (pictured below), Time, and the Boing Boing blog are among those who have already added the new share option.
Readers can save web content to their Kindle for later reading and iPad, iPhone and Android users can install a Kindle reading app on their device and so also use the button.
For Kindle users who want to save news articles from sites without the new button, they can install a 'send to Kindle' browser extension for Firefox or Chrome, or use a 'send to Kindle' email address or Android, Mac and PC apps.
Websites can get the button here and a WordPress plugin is at this link.
In an announcement blog post, Amazon asked: "Have you ever encountered news, blogs, articles and other content on the web that you want to read but don't have time to do so immediately?
"The send to Kindle button lets you easily send that content to your Kindle to read later, at your convenience."
The post adds: "No more hunting around for that website or blog that caught your eye – just open your Kindle and all the content you sent is right there."