Popular stencils
Theory of Constraints Thinking Processes
Provides a set of stencils that can be used to draw diagrams in the style of the Theory of Constraints Thinking Processes.
Simple SQL Stencil
A simple sql stencil for building tables. Fields also have connection points for relationships
Site Map (based on EightShapes Unify)
A site map stencil based on EightShapes' brilliant Unify deliverable system.
Circle Flow Arrows
Some circular arrows useful for illustrating repeating processes or flows.
iOS Gestures
The most often used gestures in iOS and other touch based platforms.
AWS Simple Icons
Icons for AWS concepts and services. Current as of January 1, 2013.
Cellular Components and Proteins
This is a collection of symbols for diverse proteins. It includes transmembrane proteins, transcription factors, kinases and enzymes as well as a representation of the nucleus and the mitochondrium. If you use this stencil for a publication, it would be kind to acknowledge the source (see website below).
Laboratory glassware
For preparation of daily chemical laboratory experiment and preparation of SOP, those are basic glassware drawings including beaker, flask, etc.
Netgear Stencil
This is another Visio stencil converted to a .gstencil. It includes Netgear switches, routers, wireless AP's, and more.