hi, you can also try curve modifier on a capsule or some other shape…
3d example: http://dl.dropbox.com/u/16486113/Blender/archivos/temp/spiral.blend
2d example: http://dl.dropbox.com/u/16486113/Blender/archivos/temp/test%20curvas%20bn.blend
new start / end bevel factor is nice and simple even if you can do that kind of things yet