Check out this timelapse of Cezar Brandao's sculpting livestream.
Cyborg Design - Concept Art Production Techniques
Instructor Michael Pedro gives a detailed overview on concept art production techniques in ZBrush and Photoshop.
Timelapse ZBrush Sculpt
Jose Alves da Silva has posted a timelapse of him sculpting a skull in ZBrush.
ZBrush 4R5 - Making Time for Art - The Dragon Flyer
The cool new features of ZBrush 4R5 are demonstrated in this video by Pixologic.