tablets/pen-displays like WACOM (for Graphic artists), Calcomp (for CAD & GIS/Mapping). different tablets for different uses. visit the WACOM site to pick yours. then try nextag.com or newegg.com to buy one. WACOM tablets give pressure readings. Calcomp is available from resellers.
uses the lcd display for a tablet. improves speed in drawing.
professional tablets for Photoshop,Painter
inexpensive tablet for people who want to use something better than a mouse with a paint program but can't afford a lot.