DesignKode offers a selection of stock icon sets for iPhone, iPad and iPod touch developers:
150 Tab Bar icons for iPhone and iPad app developers in PNG and vector SVG formats. With icons for medical, publishing, sports, games and many other topics, this set will help you rapidly develop attractive interfaces for a wide variety of apps.
Tab Bar Icons for iPhone and iPad — $60
100 PNG icons designed to fit the confined spaces of iPhone Toolbar button items. There's a wide range of images here to fit many application types. Fire up Interface Builder and get your app rockin'.
iPhone Toolbar Button Icons — $40
