+1 for the Pentel P205, it's by far the nicest pencil I have written with, and for well under $10. Writing with pencil, especially when working through a probl

+1 for the Pentel P205, it's by far the nicest pencil I have written with, and for well under $10. Writing with pencil, especially when working through a problem, lets me work more effectively. Knowing you can erase something gives you a sense of freedom to explore ideas that I don't get when writing with ink. Kind of like having an "undo" feature in an application lets you be a little more cavalier with your experimentation.