Sounds like Washington, D.C., was the place to be just a couple weeks ago. The USA Science & Engineering Festival was held on the National Mall, among other locations over the weekend of October 23 and 24, 2010. From their Website, the mission of the festival is “to re-invigorate the interest of our nation’s youth in science, technology, engineering and math (STEM) by producing and presenting the most compelling, exciting, educational and entertaining science gatherings in the United States.” Rudy Baum, editor of the American Chemical Society (ACS) publication Chemical & Engineering News, posted several images from the day at the C&EN’s editor’s blog. Based on the crowds and some of the engaging activities, it looks like it was a success. I’d be interested to try the 3D geometry activity pictured at the American Mathematical Society booth. One image from the ACS booth is extremely familiar to me. It shows children swirling food coloring through shaving cream, in preparation for marbling paper. This inexpensive activity is a fun way for students to learn about polarity concepts; it appeared in the Journal of Chemical Education in 2007 and has become a signature activity for us to share at exhibit booths and during teacher workshops. Even after at least several hundreds of times doing the activity myself, it never ceases to amaze. A free sample copy of this activity is available at http://pubs.acs.org/page/jceda8/classroom.html. Terri Taylor of ACS reported that during the festival, they marbled at least 2,000 pieces of paper, went through at least 36 bottles of food coloring, and a sizable number of 120 cans of shaving cream. She says “The oohs and aahs were worth it all.”