My latest little project is this plane adjustment hammer. (Click on any photo to enlarge).
The hammer head is made from Gidgee and brass. The striking faces are Maple and Ebony, which are attached by a sliding dovetail. For adjusting a plane, I use the Maple face for tapping the plane body and the Ebony face to tap and laterally adjust the blade. The handle is made from a piece of Victoria Ash, which is mortised through the head and wedged with Ebony. The hammer head weighs 6.5 oz.
Here are some links for other plane hammers:
Sterling Tool Works,
Lee Valley Plane Hammer, http://www.leevalley.com/en/Wood/page.aspx?p=46540&cat=1,41182