Girl Science

Science stuff in Brownie Girl Scout Try-Its:

Building Art - intended to be an introduction to the concepts of architecture, Activity 3 introduces the idea of relative strengths of shapes.
Earth and Sky - geology, astronomy, and a little biology. Activity 2 lays the groundwork for solar cooking. Activity 7 explains the difference between a solar and a lunar eclipse.
Earth is our Home - an ecology Try-It, it includes a simple solar cooking activity.
Math Fun - includes activities on measuring yourself, making an hourglass, estimation, a simple numerical transposition code, a simple spreadsheet, and money math addition.
Movers - activities involving the wind and flight.
Numbers and Shapes - tangrams, origami, sheets of paper with only one side, puzzles, rudimentary phases of the moon, shapes in nature.
Science in Action - science and technology hunt, glop making, blowing up a balloon using chemistry, paper chromatography, a magnet experiment, light and color.
Science Wonders - making crystals, making bubbles, making recycled paper, curdling milk and invisible writing, a detailed magnet experiment, and static electricity.
Space Explorer - stargazing, drawing the phases of the moon from observation, space suits, using shadows to tell time, making projectors of constellations
Water Everywhere - measuring a leaky faucet, demonstrating how fresh and salt water mix (or don't!) under different conditions.

Some links:

The Science Spot has links and ideas for activities
Plugged In! -- a Girl Science site established by Girl Scouts of Mid-Continent Council.
Girls Go Tech
Engineer Girl
Bill Nye the Science Guy -- check out his "Home Demos"!
Crafty Science from About.com
Mad Science Inedible Experiments