You on Dmoz? What about an affiliation program? And are you looking at just on-line marketing or thinking about doing any old media stuff? I will have a further thinky.
How much of a go did you give Adwords? It might be worth further experimenting perhaps?
This might be worth a bit of a read
www.cardellmedia.co.uk/
Some of it's good, some of it's tosh and purely aimed at getting you to become in "the inner circle" and other crap. The telephone conferences he does are rather amusing. It can make you think though.