Lately, we've seen the emergence of toolbar-esque social media features that enable sharing and social networking without having to install a toolbar or visit a complete site. Google Friend Connect's Social Bar enables social networking with a horizontal "bar" of social networking that web developers can place on their site. Facebook has a bar that runs along the bottom of the page while you're hanging out on their site.
Now, DiggBar comes along to make the Digg experience easier. Whenever you're on a site, you can simply type "digg.com/" in front of the URL to launch the DiggBar.
From there you can add comments, share on Facebook, Twitter, etc. or click the "Random" button to see a random Digg submission.
Of course, this is very reminiscent of StumbleUpon's toolbar, but it does make it easier to Digg. I expect we'll continue to see these social bars pop up on more and more sites.