...but i just wondered what the odds are of 3 people on a 6 handed table all having diamonds with 3 diamonds on the board?
p(3 players all having diamonds) = 13/52 * 12/51 * 11/50 * 10/49 * 9/48 * 8/47 = approx 12,000/1
There are 20 combinations of 3 players from 6, so divide 12,000 by 20 --> p(at least 3 players on 6-handed table all holding diamonds) = 600/1
p(flop all diamonds, given 3 players have diamonds) = 7/46 * 6/45 * 5/44 = approx 430/1
so p(3 people on a 6 handed table all having diamonds with 3 diamonds on the flop) = approx 600 * 430/1 = approx 250,000/1
Of course there's nothing special about diamonds, so you should divide that answer by 4 to allow for all the suits.
*The precise answer would be very slightly higher than the one above because we haven't taken into account the decreased probability of the flop being all diamonds if more than 6 diamonds are out in the hole cards, but it's close enough.
Of course, this information is pretty worthless at the table and it certainly shouldn't be used to make incorrect assumptions about the likelihood of your opponents' holdings!