FYI, this post is about the technique of v-carving; mostly carving text quickly, easily, and with a great look too. The V-Carve software from Vetric can do this technique and more. But they are two different things.
Anyway back to general v-carving.
For Mac OS X, look into running F-Engrave. It works great for generating v-carved text that can compliment any design.
Example: Use Easel to design your sign cutout, curves, etc. Then use F-Engrave to mill out the actual text.
More advance usage of F-Engrave includes importing a DXF. One can then mill out v-carve inlays using a two step process.