Putting together some UI kits for UX design inspiration. Download the free PSD here http://sarahjustine.com/2013/03/17/featherweight-ui-a-free-vector-based-and-retina-ready-ui-kit-with-bonus-mini-tutorial/
The PSD is completely vector based using shape paths for all the shapes, so it's completely scaleable to fit any design project. The blog link included a little tutorial on how to use shape paths with AI and PS, worth checking out if you haven't used this method before.