Post-it Notes certainly revolutionized the note world. No longer were scraps of paper held in place by tape or tacks the way to go when you needed to remind yourself or someone else about a chore, appointment, or other task. Post-its are self-adhesive and come in a ton of sizes, shapes, and colors.
My daughter's bedroom sorely lacked any display space for her 'trinkets' since her dresser and desk were occupied by her electronic gizmos... stereo, TV, computer, iPod dock, etc. She had framed pictures, keepsakes, and other treasures she wanted displayed and kept out of harm's way in her room.