The comment Neil makes about hating drapes is interesting.... and how they have "pretentions of tidiness"...
At the Trent Valley show this year was a modular layout, using "Freemo" standards to join lots of modules, often built by different people, to make one big layout. It didn't have drapes - I suppose the very nature of the beast makes them difficult anyway - but boy did it draw attention to the wiring, clutter and general mess underneath!!
I prefer drapes myself - except on Trade Stands - there should always be 'bargain boxes' under those, that are worth a good rummage in...!!!
I realise that perhaps I should expand a little on my hatred of drapes/curtains round the front of layouts. I understand why one would wish to present one's layout in a way where the eye was drawn to the main event and not the clutter underneath.
It's one of my pet bugbears that the appearance of tidiness at home isn't achieved by cramming all the debris of life into a handy cupboard and forcing the door closed. I don't enjoy the avalanche of crap when I open the door and the accusing honesty of the mounting piles of stuff open to view does motivate me to have a proper tidy up from time to time. Therefore my first instinct rather than trying to hide the tat under the layout with curtains would be not to take the tat to the exhibition with me. I've never really understood those that take the full tool kit, workbench, spares, spares of spares, fifteen different types of glue, scenic materials and paint to a show with them. Pare it down to the essentials and keep it neat.
I'm also rather surprised at the level of acceptance of drapes as the universal presentational tool. I can think of other ways of filling in the bit between model and floor that may suit the model better. For example Guv's 1/32 diorama of Wallingford would look brilliant on a plain plinth (think art gallery meets architects model) as I'm certain that the model making will be sharp enough to carry off a similarly sharp presentation. It would be brilliant to be able to view it in the round and the plinth with no obvious major axis would encourage this. The overall modest footprint makes it a viable method.
Jim Smith Wright's New Street likewise is a very crisp piece of model making, very urban and rectilinear, astonishingly ambitious and far too big for any plinth. However instead of curtains I could well be tempted by boards that would hang down from the underside of the front of the layout. Ideally they would be set back from the front edge by an inch or so (to help them recede visually) and I could be tempted to paint them a concrete colour to tie them in with the real life concrete construction of the station.
Simon's Pomparles Siding, has a much quirkier feel to it and being a table top layout, perhaps calls for a table cloth on the table. But perhaps the cloth should be chosen to match/complement the layout (rather than default black) be obviously a tablecloth and I think I'd like to see the layout sat centre on the table , not dragged to the front edge in a pretence that the table is part of its permanent sub structure.
I should conclude firstly with an apology to Cynric, Jim and Simon for shamelessly appropriating their models to illustrate my ideas and to say that I'm not suggesting for one moment they should do what I've suggested, more that in their position these are the sorts of ideas I'd explore.
Will I be doing as I preach? Hopefully yes; though I don't really do exhibitions and exhibition layouts I do have a narrow gauge scheme in mind that will distance itself from the dreaded drapes. Though not an exhibition layout Morfa already bares its underboard clutter (all storage no constructional untidiness) for all to see, not because I haven't got round to hanging curtains, but because I don't want them.
but they are both very small layouts.
.... drapes are also easy to fold up into a very small space for transport. Boards would be very nice but take up space, although Mike Makhis of this Parish has done a very nice job of it with his layouts, Lenches Bridge in particular. 
