What a great choice for #FF. @AnneReuss is definitely fearless and connects with people in a seemingly effortless way. I absolutely loved meeting Anne in person in New York, and am so happy that she lives in Chicago. I have already learned so much from her, and hope to see more of her :)
The answer to your question is "It depends." Depends upon your base infrastructure (do you have a web presence?, do you have a database list that you currently communicate to?, do you communicate to subscribers on a regular basis?) Amplification is a function of where and how you established yourself or your company.
As a big fan of lean marketing, I suggest test & measure each one (or each variable if you want to talk about it like an equation) after you have established you or your company somewhere (PR launch, blog, website, etc.) Make decisions based on your level of effort and the results you obtain
Margie Clayman stopped her blog but is now choosing to select how she wants to spend her amplification dollars (on Carol Roth's blog, on her company blog, linkedin, etc.) She has determined that these other platforms are optimal for her (and she simply does not have all of the time).
Andy, love the abundant ideas. I can see a lot of people having additional ideas to this post. Allowing other people to add to your list could make it one long powerful list! Let me know if you want to include something like this on list.ly. I could see this getting thousands of views and some great contributions :)