I'm partial to Jaime Vives Piqueres' "Proceduralize" macro, found here:
[url]http://www.ignorancia.org/tech_page.php?image=23&db=tips[/url]
Christoph Hormann's "IsoWood" macros are pretty neat, too.
[url]http://www-public.tu-bs.de:8080/~y0013390/iso_wood.html[/url]
