GetBrushes.com is a fresh new repository of Photoshop brushes, featuring a user forum & RSS feeds of the latest content. PhotoshopSupport.com has a brief interview with site creator Ivan Dilber.
Veerle Pieters offers a short but sweet tutorial on creating grunge brushes. It gives a great start, though I’d suggest going a degree further by playing with the scatter, spacing, and other options in Photoshop’s Brushes palette.
The Adobe Web team has now re-launched the Adobe Exchange, combining the content of the former Adobe & Macromedia exchanges. The Photoshop section now contains brushes, shapes, actions, and more.