I've been making these and they've been fairly popular.

I make a mini sharpie pen marking tool and now I have a full size sharpie version available. The combo has the pencil tool as well. This is a useful tool for tracing before you cut, making signs, the list goes on. The spring loaded design mimics hand pressure and let's you vary the writing force as well as getting more life out of the marker.

Machine Products : Cosmos Industrial, Creative and Custom Products

or cosmos-industrial.com

Thanks