Most of the current iPhone app discovery methods rely heavily on reviewers, popularity or at best personalized recommendations. None of these are as good if you want to really go deep and discover hidden gems from the huge database of 500,000 odd apps.
Consider Wootish.com to solve this problem by randomizing the app discovery process. Simply tell the website the category you want to look into, and the tool will bring random applications to the fore. Who knows - you could end up downloading the next big app that nobody talks about.
Do let me know if you find this useful. Also share your valuable feedback.