You can bookmark posts with the icons or threads with the linkback feature that is next to the thread tools.
These are social bookmarking sites that let you keep bookmarks from sites that support them. It also helps those that are not able to view at work due to some of the material on here.
There is also going to be a feature in which you get credit for the thread. So if someone diggs your thread on digg.com, there is going to be a counter that gives you (the author) credit. Its basically acknowledging that your thread is worth something to everyone out there and people are "approving" it. The more you get dugg, the more people see it.