using foam rubber, covered it with nylon / tricot fabric and stuck felt dots on it.
I challenged the dancers to choose "odd" (standing back to back) or "even" (standing side by side). It was most successful, and over rather quickly 'cos most dancers who stopped to listen did so side-by-side, and stayed that way - - and "odds" was thrown first!!! LOL
An more ideas????

Probably stolen from Arthur Murray is Whisky, Scotch, Soda.

Play a song, dance should travel. Foxtrot is usually what we play. Play it for a time, and then the MC yells one of the above.

If ..... is yelled, the couples do.....:
Whisky ..... guys on one knee, ladies sit on offered knee. Last one down is eliminated. Fall off eliminated, etc.
Scotch ...... Couples must freeze.
Soda .... Switch partners. Last couple to meet is eliminated, might want to do a count down, that way you can eliminate more couples.

Soda is usually the easiest way to eliminate couples, but watch out for ladies with claws, ehh...nails. For fun, throw in some other words (rhyming??) and eliminate the ones who react. It gets really funny when you get fewer and fewer couples, the dance circle gets smaller and smaller.

Another one (if you can have a quick sweeping), is tie balloons on a short string to the leader's leg so it follows behind them. Last balloon not popped wins. Haven't actually seen this one done, but I hear it's really hilarious, if there is just a bit of helium in so the balloon floats just above the floor.

Later....

At our studio we use the card option, with 'Joker' allowing everyone back on the floor. Also, when the numbers are reduced sufficently, we change from suits to 'black' or 'red', to reduce the remainder by half. We reduce to the last four couples, who then receive a small gift for each couple. To add interest, sometimes we have , 'hug', 'back to back' or 'lady on knee',as the options.

have oranges!!! LOL.
Interesting Idea - I have seen something similar done with balloons!

How about have each couple dance with an orange between their bodies (in standrad dances only). When the orange drops to the floor, their are out!!! ;-p. Then after the dance you will have fresh orange juice for a couple of weeks.

Come to think of it, do you have oranges in New Zealand? Using Kiwi might be too messy!!!!

When you have 80 couples on the floor, you need to use a group of 3-6 judges like those in the real competition. Let the judges pick 6 finalists or 12 for semifinal. etc. etc.

You could make the first round eliminate 3/4 by making those in the chosen corner stay on the floor while the rest sit down.

An alternative method of eliminating a corner, introducing an element of 'skill' is to have one person from each corner roll an object at a bottle placed in the centre of the floor. Nearest wins or farthest loses. If you make the rolled object difficult to roll, such as a lemon, it adds to the fun.

Howard