Here's the single-path method, with random choices determined for each 
trace level for the entire image per-pass, with 64 samples and taking 4m 
11.16s to render:

-- 
Christopher James Huff <cjameshuff@earthlink.net>
http://home.earthlink.net/~cjameshuff/
POV-Ray TAG: <chris.huff@tag.povray.org>
http://tag.povray.org/