Popular stencils
Systemic Structural Constellations
A stencil for systemic structural constellations in coaching or family therapy.
Cisco CVD 2014 LAN Switching Icons and Clouds
Cisco released updated CVD Icons in many formats, but of course, no Omnigraffle stencil. These are built from the PNGs. http://www.cisco.com/c/en/us/solutions/enterprise/design-zone-smart-business-architecture/cvd.html This is the LAN Switching Icons and Clouds section.
Boyd Hobbs' Grip 2
Large Frames and Grip Stand, Diffusion, Bounce, Solid, Lighting, Film and TV, Grip
Designa PM100 equipment
Stencil for creating parking lot equipment scheme based on Designa PM100 equipment.
ShoreTel - ShoreLine/ShoreGear VOIP stencil
This is a Visio stencil that I had to export in Visio and Save As an XML stencil. I then converted that in OmniGraffle Pro to a .gstencil. Stencil contains a few Shoreline and Shoregear voice and T1 switches, various ShoreTel phones and generic buildings.
Minecraft
I needed a Minecraft stencil for organizing my thoughts. Just a bunch of random blocks, but someone might find it useful.
BS2 Board of Education (Serial)
Parallax's Board of Education (Serial) symbol.
Nortel Networks
Modular and normal L3/L2 Nortel Network switches
Piano
One octave of piano keys