Pete Ashdown (The xmission guy) has an interesting article on using community sites like slashdot in political campaigns. His organization had a concerted effort to get a story slashdotted. The effort resulted in people making contributions to his wiki and a rather impressive chunk of free advertising.
BTW: Mr. Ashdown is running for the U.S. Senate.
I guess we should expect to see savvy politicos staging different efforts to manipulate the world's supposedly unbiased community web sites.
I do like Mr. Ashdown. I appreciate that he is honest and open about his web campaign efforts. His blog entry shows the thinking going on in the great public opinion manipulation game.
Every web site, of course, is open to manipulation. Personally, I like to promote small independent web sites ((plug for Community Color) as the amount of manipulation gets offset and diluted.