Someone posted this link to a video of a rather impressive
smoke generator on one of the Yahoo groups, gather it costs 140 euro and is for 00 gauge and larger.  Hope they are working on a smaller version as the current crop of smoke generators for N gauge only last a few minutes.

Wow!    the startup is really impressive! 
Gerard

I can imagine that would become a health hazard very quickly unless there was adequate ventilation 

cheers John.

I bet it would look more impressive with the loco's moving rather than on a rolling road, is there room in an n gauge  diesel for the sound and smoke generator? curious.

Strewth!
It ought to carry a Government Health Warning

Actually I think it's a secret steamer as at about 1.50 you can hear the fireman breaking up the coal

Went to the model boat show last year and saw several "smoke" generators for model boats. They worked on ionising water into droplets and were very impressive, quite small, but I don't know if they would be suitable for N gauge. The advantage is that they are odourless and non toxic.

I won't be fitting them to my diesels as I think it might set off the smoke alarm!
Seriously, can anyone imagine a depot with, say, 5 or 6 locos smoking like that in a small room?  Not a good idea, in my opinion but, what the heck, it's your model, not mine, after all.

When I was a kid I'm sure I was addicted to the smoke from those smoke generators Triang used to fit to their Britannia's and Jintys 

Smokin' ! 

Could account for my current condition 50 years down the track...