Our family has participated in this for the past 5 years. Anyone else here ever participated in it?

From IndyMedia.org:

International Buy Nothing Day To Be Celebrated In 55 Countries

In observance of what may very well be the most important holiday of the year for the anti-capitalist movement, people in at least 55 countries will celebrate "International Buy Nothing Day" this weekend. Begun in 1993 by the founders of Adbusters, the concept has taken root in diverse communities and manifested in multiple ways in cities throughout the world. In Europe, International Buy Nothing Day (BND) is celebrated the last Saturday in November (the 29th) while in the United States and Canada the event has coincided with the day after Thanksgiving. The latter date was chosen in response to the fact that the last Friday of November has become, due to intentional marketing strategies, the "biggest shopping day of the year" in the United States. BND was conceived as a protest against the religion of consumerism, and the multiple ways in which the imperative to shop is implicated in systematic violence throughout the world. In its positive aspects, BND is a celebration of life, community and local autonomy.

Meanwhile, a group of "anarcho-situationists" from Montreal have decried Buy Nothing Day as a "misplaced...notion of consumer empowerment." Seeking to raise the bar on anti-consumerist action, they have called for Steal Something Day, to be held Friday, Saturday and everyday.