I’ve been using a small app called dockless. Dockless hides the icon from the dock…that’s all. But it does it great and it’s free.

Dockless is a little app that does what some people have always wanted – remove certain applications from their dock. Dock real estate can become precious, and some apps don’t make a whole lot of sense sitting there. That’s where Dockless comes in. With Dockless, any OS X application can be made to show in the Dock or not.

Download dockless here