I've long blogged things to let anyone who stumbles across the post know that I like or dislike something. But recently, as I understand Google's page rank, it's become apparent to me that when I post an entry with a link to something, (say magnatune.com), it's actually a vote for that thing. It gives it slightly increased legitimacy in search-result terms.
Spammers have actually been using this fact to try to load up blog comments and wiki posts with links to their site. I had one such comment that I promptly removed.
On the positive side, there are linkblogs: blogs that are nothing but links to things that the blogger finds interesting, but has little or nothing to say about. (Or, in Robert Scoble's case, wouldn't be able to find time to comment about, and still have time to sleep at night.)
Just one more aspect of our new participatory culture.