A friend of mine runs http://www.udm4.com and we've talked about running an ad on there since its primary audience is developers (nevermind the fact that I don't really like the menu). Other than that, try to partner with good development shops that do online stores ... I have a few in mind.

Any other ideas, besides taking out the obvious ad on google? I really don't want to screw with trying to get high keyword ranking via the SEO black-magic route.