On 30/06/2010 21:49, John Rumm wrote:
more than one intermediate switch, can anyone give a wiring diagram
(preferably not ASCII as I can never make head nor tail of them)?

Here are some we drew earlier:

http://wiki.diyfaq.org.uk/index.php?..._Way_Switching

That page should probably say something about the flickering problems
you can get with low-energy fluorescent fittings - the capacitance of
all those conductors running parallel within the 3-way cables can throw
them in a tizz.