I massive frustration with designers in Photoshop is the inability to change the radius of corners after you've made the shape. This very neat little script completely changes this annoyance.
Corner Editor is a free Photoshop script which allows you to style the corners of shapes how you like - after you've made the shape. It allows you to have different corner styles for each corner on a shape, you can even apply the same style to multiple layers at once.
This is a must have for any Photoshop user.