Environmentally Safe Weed Killer

I often heard and recommended vinegar as a 'greener' weed control alternative to chemical herbicides. Although I have never tried it some additional information on the topic is below.
(from natorp's garden center weekly newsletter/ blog http://natorp.com/wordpress/#tmp)

“Tell me more about killing weeds with vinegar. Does it matter what type of vinegar? Will it also kill the grass?” -No and yes. Doesn’t matter what type of vinegar is used, but the higher the percentage of acidic acid the better it works. And it is a non selective vegetation killer, meaning it kills what you spray it on, weeds, grass, and all. Vinegar is strictly a foliar kill, and does not kill the roots.