Taking the iPad2 for a spin!  SketchBook Pro app  ($4.99) +  Pogo Sketch  ($14.95) 
 Verdict: Great for quick sketching & using basic colors. Small learning curve for navigating the UI via gestures, but once you get a handle on them the workflow feels fairly fast and efficient.  
 For fully customized color palette & detailed line art, bring it back to the desktop. The app exports to PSD so you can continue to edit it in Photoshop or  Sketchbook Express/Pro for Desktop . 

Taking the iPad2 for a spin! SketchBook Pro app ($4.99) + Pogo Sketch ($14.95)

Verdict: Great for quick sketching & using basic colors. Small learning curve for navigating the UI via gestures, but once you get a handle on them the workflow feels fairly fast and efficient. 

For fully customized color palette & detailed line art, bring it back to the desktop. The app exports to PSD so you can continue to edit it in Photoshop or Sketchbook Express/Pro for Desktop