Here's Robert Reich from last year, about celebrating labor on Labor Day:
Digby has clips of Barbara Kopple and her Oscar-winning documentary Harlan County U.S.A. (I met Kopple years ago, and she's a cool person in addition to being a great documentary filmmaker.)
Digby also passes on "The True Story Of How One Man Shut Down American Commerce To Avoid Paying His Workers A Fair Wage" by Ian Millhiser and "Anti-Labor Day" by Ed Kilgore.
ThinkProgress also offers "Conservatives Protest Labor Day by Staging a Work-In" and Daily Kos Labor gives a reminder of what unions do.
At the Campaign for America's Future, Dave Johnson provides "Why Fight For Unions? So We Can Fight An Economy Rigged Against Us."
At Pharyngula, PZ Myers has posted Sarah Palin's incoherent Labor Day video (Pailn tries to portray herself as pro-labor but opposed to union leadership, and drops entire words in addition to her "g"s. The comment thread is fun, though.)
Erik Loomis' series, This Day in Labor History, is well worth a look.
The PBS series American Masters recenty aired an episode on Depression-era photographer Dorothea Lange, and Yale's site, Photogrammar, in collaboration with the Library of Congress, is "a web-based platform for organizing, searching, and visualizing the 170,000 photographs from 1935 to 1945 created by the United State’s Farm Security Administration and Office of War Information (FSA-OWI)."
My most in-depth post for Labor Day was this 2011 post.
If you wrote a post celebrating the day, feel free to link it in the comments.