Actions are one of the most powerful and time-saving features of Adobe Photoshop.
Everyone has their own favourites, but if you are looking to find some additional ones, here’s a couple places hosting downloadable actions:

Adobe Photoshop Exchange
PhotoshopSupport
ActionCentral
About.com
Action FX
The Light’s Right Studio
Fred Miranda

If you know of any other good sites or actions you find useful, please leave a comment.

GREAT LINKS ACROSS THE WEB is a new blog feature where I will post links to useful sites.