The little plastic cutting board that I have that is way too small.  I use it almost everyday so you would think that I would have bought a bigger and better one by now.  I never think about it until I'm chopping up some veggies.

I also agree with Buggheart about the cheese grater.  I've been making a lot of zucchini bread this summer and it scares me each time I use it.  I end up wasting a big chunk of zucchini because I'm afraid of shredding my knuckles.