Top Rated
SimpleWireFrame
Large stencil with lots of elements. The screenshot does not do it justice since it is so large.
Wireframe Sketch
Use to create printouts for your paper-protyping or interactive mockups that can be exported to clickable pdf in Omni. Please let me know of any omissions/additions and I'll update the stencil.
Apple Elements
Stencil of additional Apple hardware and misc. networking components. Excellent for creating physical diagrams.
Form Elements
Form elements stencil from the Design Stencil kit in the Yahoo! Design Pattern Library.