Kevin Wick has posted a very nice sketchy-styled Axure library.  I highly recommend it.
Prototyping in a very low-fidelity visual style generally helps your stakeholders provide feedback at the right level, as discussed in this article, and has been adopted by many other design tools, notably Balsamiq.

Web applications and sites these days are using many social features. This library, compatible with Axure versions 5.5 and up, contains many of the standard widgets you will need to prototype basic social functionality.
You’ll find a lot more than nice looking stencils – these widgets have polished interactivity, for your prototyping and usability testing [...]

About a month ago, the folks at Zurb published a nice article about sketching wireframes.  I went ahead and purchased some new sketching items including a nice thick sharpie and a cool gray “dropshadow” pen.
The difference in my sketches is incredible.  Zurb hits the nail on the head, saying, “Although we advocate keeping things as [...]

Whether you’re a new or experienced Axure user, the following links will help you become a library-wielding, animation-blasting, prototype-perfecting Axure ninja.  I’d recommend starting with the training items to get used to the basics, and then moving into the pattern libraries with more experience.

This update includes some great new pattern libraries posted by the community. [...]

Despite the imminent danger of this blog becoming solely focused on Axure, I have a quick update:
A big thanks to Richard Tsai over at Userxper for translating the pattern library into Traditional Chinese.  We’re going global!

More patterns for ya!  This is Version 2 of the first Axure stencil library.

Demo the HTML OR  Download the Axure (.rp) File

Update: This library is out of date, please see Version 2.
I am excited to present: The first Axure stencil library.

Demo the HTML OR  Download the Axure (.rp) file