Newest stencils
xHTML Content-out Approach
A simple set of stencils good for analyze web design layouts according to the Content-Out Approach, as seen on Transcending CSS: the fine art of web design by Andy Clarke (http://www.transcendingcss.com).
FMC v2
Stencils for the Fundamental Model Concepts - http://www.fmc-modeling.org/ Version 2 contains additional stencils for Petri Nets.
LOOPS
Use these blocks to make various loop shapes.
Django Admin
Stencil featuring the out-of-the-box UI elements available when creating admin interfaces for Django sites.
Class Responsibility Collaborator (CRC)
Class Responsibility Collaborator Models.
Learning Activity Patterns
Visual vocabulary for modelling Learning Activity Patterns in e-learning 2.0 environment. Created in the context of iCamp project (icamp.eu).
iPhone Wire Frames
This is a basic stencil for creating wire frames for iPhone optimized web sites (from April 2008) Includes standard components like form fields, buttons, dialogs, key boards, lists, loading icon, selected state. Any feedback would be appreciated, and I will make appropriate revisions.
famfamfam Flag icons
Port of the Flags library from http://www.famfamfam.com/lab/icons/flags/
SimpleWireFrame
Large stencil with lots of elements. The screenshot does not do it justice since it is so large.