If you are out east in New York city May 29 through June 1, you will want to check out the events of The World Science Festival. The event features a variety of scientific and cultural events spread out through Manhattan with the goal of connecting the public to science.
The festival is set up to run throughout the time much like your typical arts festival with many of the events bridging that geek gap of arts/performance/tech/science. "Mathemagician" with Arthur Benjamin, "I.J.K." a physics/math performance, and "Bioart in the Age of Terrorism" all seem to have broad appeal. Some of the pretty mainstream slate delves into heady topics like "Music and the Brain" with Oliver Sachs. There is also a slew of smaller events that would be attractive to geekdads and kids alike, plus a free street fair around Washington Square sure to have tons of science-related goodies. As their website says: "it’s fun, it’s science, and it’s free!"