When I first heard about the Sharpie Liquid Pencil, I was both curious and skeptical. When you really think about it, it's basically and erasable pen that just happens to use liquid graphite instead of ink. Paper Mate has been doing erasable ink for years with it's Eraser Mate.
What interested me was Sharpie's "Pencil" spin on the concept. Instead of competing in the same erasable market against Paper Mate, they decided to take on the mechanical pencils of the world. The idea of never needing to reload a broken lead is amazing to think about. I also read that after a few days, the liquid graphite becomes permanent - another brilliant concept. You get the freedom to change your mistakes as they happen, but you get the benefit of long lasting ink.
I finally got hold of one and here are my thoughts. My first impression is that it doesn't write as smoothly as other pens. I had to shift my perspective and compare the feel to a mechanical pencil instead. It actually writes smoother than most consumer grade mechanical pencils. The liquid graphite erases really well - almost better than traditional graphite. Unfortunately, it doesn't erase as well after only just a few hours on the page.
Another benefit with the liquid graphite is that it doesn't smudge like regular graphite. I haven't given it a proper drawing test, but if this proves to keep my hands cleaner, I would completely convert over.
One final observation is that, although it wasn't very expensive ($4 for 2 with extra erasers), the quality and feel was a bit flimsy and cheap. I particularly didn't like the looseness of the eraser end once the writing head is deployed. You'd think that a rock solid brand like Sharpie would have figured out a better solution for that.