This seems to be a pretty good way to create one way backlinks to your site.

Also seems to be a good way to find relevant content to post on your blog.

While this is totally "white hat" -- I could see where some people could use these methods for spamming.

With the way Blogs ping the directories when a new post happens, I can see where having a few links on these "network" sites would help dramatically.

Using "Anchor Text" that links to the subject site should help greatly in letting Google know the subject (theme) of the site.

This is covered in the Clipmarks Unleashed report.

Not sure why it is called a report -- it is 40 pages of "how to" information and screen capture images on how to set up a [URL=http://www.clipmarksunleashed.com/clipmarks