Innovation of Eraser

Because of the progress of digital technology including a personal computer and a PDA, my chance of using a pencil and paper has decreased dramatically. However, these primitive tools, which I have been accustomed to since my school days, still have a great advantage to those digital tools. When I think about abstract ideas, a pencil in my hand is way more helpful than any modern computer. One reason is that I can get relax with a pencil while I feel more or less nervous in front of computers. Another reason is that digital tools are far from perfect and they can't be transparent while analog tools are so simple that I don't have to be conscious about them. That's why I sometimes enjoy shopping in a stationary shop browsing interesting analog tools. Today's game was this innovative eraser. It doesn't look like an eraser, but it can erase pencil lines very perfectly. It is composed of a sticky roller and a plastic cover. Can you guess how it works? All you have to do is roll the roller on pencil drawings which you want to erase. The sticky roller catches the lead of a pencil without creating dust and damaging the paper at all. If the sticky roller becomes dirty, you can roll it on a piece of duct tape to remove the lead and you can use it again and again. It costs less than $2! Isn't it cool?