Yeah - agreed... they somehow look tacky to me, but every time i went to a ball where there was a photographer there he/she used the blue/white cloud background with the train.

Depends on the event i suppose and the people there / the style you want to come out of it with.  but that goes into the realms of the client saying "i didnt expect that you would use a white background - i wanted the blue and white one - this photo sucks"... ie client expectations of what background is generally used at these events. Meaning that the aim to please as many people as possible (albeit with the boring run-of-the-mill background) method is probably the best route.

"In every colour, there's the light.
In every stone sleeps a crystal.
Remember the Shaman, when he used to say:
Man is the dream of the Dolphin"

Rich Meadows Photography