Popular stencils
Tabs
Tabs stencil from the Design Stencil kit in the Yahoo! Design Pattern Library.
Apple Hardware Elements 2010
A collection of official Apple hardware icons, for use in physical network diagramming. Includes the following: iMac (all generations) MacBook Pro (unibody, previous generation) MacBook (unibody, previous generation) PowerBook (all generations) AirPort Extreme, Time Capsule Apple Cinema Display iPhone, iPad, iPod Touch XServe...more
Touchscreen Hand Gestures
A collection of drawn hands for documenting touchscreen interactions. Includes point, tap, pinch, spread, drag.
Annotations
A set of annotations for photographs and diagrams inspired by the excellent annotations available in Little Snapper from RealMac Software.
Web Form Elements
Edward Anastas has put together a handy stencil composed of often-used elements in HTML and web page forms: radio buttons, checkboxes, combo boxes, entry fields and text areas. Nice looking and Aqua, to boot.
Web Detail Flowchart
The page title, page file name and page description area labels are editable. I added an example of how I use this stencil. Feel free to use as you like though.
OS logos
A collection of OS/hardware logos, including Sun, HP, Linux, Red Hat, FreeBSD, Windows, Debian, Darwin, IBM, and VMware.
Pretty Urban Building Icons
A collection of icons of urban buildings
Django Admin
Stencil featuring the out-of-the-box UI elements available when creating admin interfaces for Django sites.