One of the oldest and most useful features of my blog is my Linkblog. That's it over in the sidebar, you can see it here or subscribe to the RSS. Not much to the HTML view, it's just a delicious page, but really it's a blog. I post several links to it every day and the descriptions are written for an audience, you. These days it's got better content than this main blog of mine.
Next MediaLinkblogging is an old blog form, arguably as old as blogging itself with Jorn's pioneering Robot Wisdom. I read several linkblogs every day: Waxy, fakeisthenewreal, Jeremy Zawodny, iamcal, David Carlton, and an aggregation at HotLinks. (Jason Kottke and Anil Dash both used to be masters, but have rolled their links in to their main blogs.)
It strikes me how much linkblogging is like Twitter. A short, informational message you broadcast and then forget. Easy to create, easy to read, information lite. Linkblogs are different from Tweets in that they pivot around the link, a single chosen URL. And they're not really suited for reading on a mobile, usually the linked site is a full web experience. I like linkblogging as a medium, I wish more people did it.