It took me about a second to think of Dixon Ticonderoga pencils. These are the perfect nexus of good and cheap. These things have the critical features one looks for in a writing instrument, my favorite of which is that I can put it in my electric pencil sharpener and the lead never snaps just prior to the point at which it becomes sharp.

And these guys finally figured out something useful to do with that pink, rubbery, knob at the end of the pencil. I've never been able to figure out what this rubber piece is for on other pencils. On some, it works like a highlighter, but not as well -- leaving this pale, pinkish/carbon smudged mess all over the page. On others, it works like the worlds worst paper shredder, ripping through the page haphazardly, but not in such a useful way as to render the contents securely shredded. On Dixon Ticonderoga pencils, this rubber knob removes any pencil markings that were made in error. It's incredible!

The best part, though, is that you can get a box of almost 100 of them for around $14.