A while back, I wrote a post "15 Suggestions for Marketing your iPhone Application" in which I suggested you work on having a website for your iPhone application so that you can get found in Google.
While a lot of this is still relevant, I did notice the article "App Store SEO: The Impact of iTunes Web Preview" which shows that Apple's new, rich web previews take care of a lot of the criticisms I had of their launching pages.
I still think it is a good idea for an iPhone (or iPad, for that matter) developer to have their own website, where they have much better control over their content and can do more to convince the website visitor how cool your application is. But at least Apple's change will help as well; the advice in the article I've linked to is good stuff!