I have.....and i don't think it is all that effective...you really have to think about what
you are doing when it comes to web 2.0, spun articels and scrapbox commenting..
If google work out what you are doing they deindex your web 2.0 and if the 2.0
site admin see what your are doing they delete your account.
The day of posting, spinning and comment blasting crap are over...
you have to start delivering natual and quality stuff with your blackhat tools
or all of your hard work get's kicked into orbit...
some of my 2.0 blogs are floating near the sputnick satalite LOL