Hartmut Holzwart and Jason Summers have been investigating possible shapes for 2c/4 "greyships" that include an extensible striped region of half-ON, half-OFF cells. Triangles, diamonds, and other shapes are possible.
This technology can be extended to produce more complex shapes with a variety of slopes. Some components also exist for a ship traveling perpendicular to the "grain" of the stripes, instead of parallel, but currently not enough to produce a complete ship. See this blog for details.
Update: See the "Greyship Update" posting on September 6, 2005, and also later greyship postings on December 16.
