Backlinks are nothing new, and many blogs are already utilizing them, but they are quite helpful in building traffic for your own blog. They enable you to keep track of other pages on the web that link to your posts.
Lets say that one person (Jim) writes a blog entry that another person (Ron) finds interesting. Ron might then write a post about Jim's post and actually link to it. Jim's post will reflect the link and possibly a small snippet of text. This helps to relate discussions that occur on different sites.
The backlinks setting can be found under the Settings Comments tab, and consists of a single, simple option to turn it on or off:
If you click the link, you will then be taken to the actual post page.
Hope this is helpful,