I don't know if anyone's noticed this or not, but if you grab the little vertical line between the active tasks and the first icon (it's near the left hand side, if you have at least one program running)... by dragging the mouse up and down, you can resize the overall dock.... very cool
you can actually make it really small, but you have to do it by clicking the top of the line, and dragging down as far as your mouse will go - you may have to do it multiple times, since your mouse won't go down lower than the bottom of the screen