The Qing Ming festival, a Chinese tradition that is celebrated on April 5, has long been seen as a way to earn respect and good fortune for future generations. It is derived from Taoism, Buddhism and regional folklore.
There are variations of the custom -- some over time, others based on geography -- but the purpose is universal: paying respect to one's ancestors. Families clean their ancestors' burial sites and decorate them with the deceased's favorite treats. Another tradition is burn fake dollar bills and other material goods, for the ancestors to enjoy in the afterlife.
Lately, some Chinese families also have burned iPhones, Louis Vuiton belts and BMWs, all made of paper.
You can read more in an article by Esmeralda Bermudez in the Los Angeles Times at http://www.latimes.com/news/local/la-me-tombclean5-2009apr05,0,3266485.story.