Thanks for the really good ideas. If you click on the flickr link in the post you will see much higher resolution versions. Also, I have been experimenting with different colour palettes in an attempt to combine art with science. I guess I'm trying to do something different, and the results won't appeal to everyone. For example, look at the unusual rendition of the Rosette Nebula here:
http://www.flickr.com/photos/mlparkinson/6988913495/
Strangely, my favourite rendition is the R, G, B = OIII, Blue, H alpha version. I plan to produce more images using this colour palette.