1.  A big slinky for the wave demonstration.
1a.  A strong spotlight for the prism demo so you can make a tall,
vertical spectrum.  Also, colour gels for the spotlight to show how each
each colour is made by removing light from the white beam.
2.  Have enough pocket slit spectrometers for each kid.  That way they can
look at different light sources to see what colours are in each.  We could
calibrate them or give the kids reference light sources so they can
calibrate them.
3.  Have a fluorescent lamp, incandescent bulb, sodium vapour lamp,
computer monitor and LED clock face as light sources the kids can examine
with their pocket spectrometer.
4.  Get a heat lamp.  You can feel the radiation, but you can't see it.
If we get two clear sheets of plastic (with different IR absorption) we
should be able to get kids to see that IR can be absorbed too.
5.  Get a thermal imaging unit and hook it up to the computer monitor.
That way kids can see themselves in heat, and try to work out what absorbs
heat and what doesn't.
6.  Set up a thermal sensor like the bathroom handwashing system so kids
can try to see what sets off the sensor.  They can put a piece of metal
in, then hold it in their hands and put it back once it's warm.  They can
also shine light off the metal to see if the sensor responds to that.
7.  Get a dark lamp.  Kids can fluoresce themselves, play with beads and
soap powder under the lamp to see what colours come off.  If we could get
some phosphors it makes a great way to explain how TV's work.
8.  Get some photos of flowers taken under UV light.  Get some photos of a
forest taken in IR.  Explain to kids how bees see in UV.  If we had a
really good phosphor we could do a UV imaging system.
9.  Show the kids how to make an intensity meter using neutral density
filters.  Let them try to work out the dimmest light they can see and the
brightest.  Alternatively, give them an LDR and let them use the
multimeter as an intensity meter.  Get them to compare room lighting to
sunlight.
10.  Get the kids to combine their LED with an LDR to make a motion
detector.
11.  What about a collection of cool fabrics, plastics, metals, CDs, opals
and other things that have weird colour properties.