David Howarth has a neat variation on the reflective needle...
http://www.stargazing.net/david/spec...ctroscope.html
If this is set up and a 80mm+ camera lens fitted with a SA100 imaged on the spectrum you'll get some "Ohhhh Ahhhh" images.
The other alternative is a pencil sharpener slit (blutack etc) in a box, long enough to allow say a 50-80mm camera lens to focus on it.
Illuminate the slit from the Sun, and again use the SA100 on the lens....