I thought I'd start a free plug-ins list. More is better right.
Whats yor favorite?

From 'Little Ink Pot', http://www.littleinkpot.co.uk/FreePlugins.htm

- Xpose is an exposure adjustment plugin. It was written to offer quick adjustment of highlights and shadows with a rapid preview feedback and a simple, intuitive interface. With just a few sliders you can attain better exposure of your digital photos -
CODE
http://www.littleinkpot.co.uk/xpose.zip

(317 kB)

- Thredgeholder providing edge detection that's simple to use but highly effective -
CODE
http://www.littleinkpot.co.uk/thredgeholder.zip

(365 kB)

- Chalkaholic renders chalk and charcoal type effects with artistic panache and flair. Providing uniquely effective artistic rendering options, Chalkaholic is the essential addition to any digital artist's effects collection.
CODE
http://www.littleinkpot.co.uk/chalkaholic.zip

(414 kB)

Simply unzip the downloaded files into you Plugins folder, such as
"C:\Program Files\Adobe\Photoshop\Plugins"