I found this from Problogger. After all the serious mumbo jumbo about PageRank ups and downs, here is something to cheer those who lost their PageRank. It may be good to mess with PageRank logo. 
or
No idea why your pagerank drop?
Or some Black Hat will do the trick.
Unless you always go by the rules.
Maybe you can trick some advertiser to buy link from your website
Visit SportSayer for the full list.
