Martin Luther King, Jr. contains ideas about arts and crafts, bulletin boards, discussion topics, language activities, songs and more. Go to http://www.geocities.com/Athens/Troy/9087/mlk/.
The Seattle Times features King's voice, a photo gallery, information about the holiday, and an interactive classroom section. Check out http://seattletimes.nwsource.com/mlk/.
You'll find a Timeline of the American Civil Rights Movement at http://www.wmich.edu/politics/mlk/.
You'll find a ton of connections (a hotlist!) to Presidents Day sites at http://www.mcps.k12.md.us/curriculum/socialstd/Presday.html.
Take a Presidents Day virtual field trip for primary students at http://score.rims.k12.ca.us/activity/presidentsday/.
Lots of activities are waiting for you at http://www.kidsdomain.com/holiday/presday.html.