FranticFish - 7:25 am on Nov 26, 2011 (gmt 0)
Google ranks businesses in the '8 pack' Places results that don't have websites. They use unlinked local directory listings to do that - so must be using the tel number, address, and possibly business name.
I realise this is a different algorithm, but with the emphasis on brands these days is it such a leap of faith to think that a brand mention (assuming your brand is sufficiently distinct) would not count for something? On a high traffic popular relevant website, for ever, I personally think that $100 is a good investment.