Here are some links to older writings that are online at the moment (December 2008), though one never knows how long this form of publicness will last.
010 publishers has put the entire book The Urban Condition (1999) online, including my article The Invisible Work of Art, on works of art in urban "public space":
The somewhat more gothic essay The Conspiracy of Publicness from Open no. 7 (2004) is online at the official web site: http://www.skor.nl/article-2871-en.html
A 2004 essay on nostalgia, Happy Days Are Here Again, is still online at http://d396752.u88.clusternet.nl/page.php?node_id=113&l=nl. The text appeared in Metropolis M; at the moment I can't find the magazine in question, so I cannot check the number of this issue. I do recall that the design fascists who had free reign at the magazine thought it would be a cool idea to use different fonts for the names and bands, TV shows, and the like. These interventions are thankfully absent in the online version.
Someone at Berkeley put up a PDF (with some passages marked in yellow) of The Feathers of the Eagle (also known as Appropriation Mythology) from New Left Review no. 36 (November/December 2005): http://bcnm.berkeley.edu/cnm201/readings/Lutticken_Feathers.pdf