Autodesk Inc has SketchBook Pro (iTunes Link) in the iTunes App Store for $2.99 for a limited time.

Autodesk SketchBook Pro for iPad is a professional-grade paint and drawing application. Using the same paint engine as its desktop counterpart, SketchBook Pro delivers a complete set of sketching & painting tools through a streamlined and intuitive user interface designed exclusively for the iPad experience.

Whether you are an occasional doodler or a professional illustrator, SketchBook Pro transforms your iPad into the ultimate digital SketchBook.