Thanks Zaphod77! (Was 'Zaphod42 taken? ;-)
AND thanks to everyone else as well.

'In my own case, when it seemed to me after a long illness that death was close at hand, I found no little solace in playing constantly at dice.' -- Girolamo Cardano, 1563

Everywhere a class three slot is allowed in the USA, to the best of my knowledge, it must be truly random, with independent reels.
Class 2 slots are not really slot machine,s they are bingo games in disguise.
Forgive me for saying 'slot machine' when I meant 'class III gaming device' :)

'In my own case, when it seemed to me after a long illness that death was close at hand, I found no little solace in playing constantly at dice.' -- Girolamo Cardano, 1563

Well, if a UK style hi tech fruit machine were legal to operate in the USA, i'm pretty sure they would be operated, as they have an addiction factor much stronger than the US random ones.
Therefore I really do believe that every slot machine that's actually a slot machine, and not a pulltab/bingo internally has to be the way they are in Nevada to be legal.

In Australia, many slot machines have bonuses that can come down randomly or on free games. All machines are 15 -25 lines and there are almost no traditional 1 line slots anywhere. The reason you would lurk is that the minimum and maximum random bonuses increase to a certain point depending on the money put into the group of machines. So, sometimes the maximum will be $100/$500 for the mini and max. So if it was at $44/$300 it isn't as good as a bet compared to the machine that hasn't paid in a while which is at $100/$500. So going on a machine after someone has been playing and losing for a while will result in a better win if you win the bonus. I always go for a machine thats maxed out on bonuses or closed to max out. However, I never play slots with my own money anyway since it is a sucker bet. My dad loves slots and somehow he wins reasonably often... and he is prone to gambler's fallacy. He has won significantly large amounts up to $16 000 though. Because the probabilities are the same, it doesn't really matter when or what he chooses to play. If he feels better playing a particular machine because of an error of reasoning, it doesn't make much of a difference.
It is also relevant that some machines have different rules that will actually result in a better house edge making it worse off for the player and simply not worth playing. Slots is big business in Australia. It is the most popular game since it is available everywhere outside casinos. Australians lose billions each year on slots. Some machines rely on free games, others on random bonuses, and others simply on getting the right combinations. Slots at casinos in Australia are, in my opinion, because of the way they run, completely sucker bets for anyone who tries. Slots in various clubs in suburban areas are far more fair and result in an alright bet for those gambling. Never play slots in a casino in Australia ever. Go to the tables.

Double Action
Games 3, 5, 7, 10 & 12 Pay Double
Coverall $250 Blue & Red * $500 Green & Tan
2nd Chance $250 Any Color Card

Regular Pay
Coverall $250 Blue & Red $500 Green & Tan
2nd Chance: $125 Blue & Red $250 Green & Tan

Double – Triple Action
Games 1, 2, 4, 6, 9 & 11 Pay Double
Games 3, 5, 7, 10 & 12 Pay Triple
Coverall $250 * $500 * $750 * $1,000
2nd Chance $125 * $250 * $375 * $500
3rd Chance $125 * $250 * $375 * $500

Regular Pay
Coverall $250 Any Color Card
2nd Chance: $250 Any Color Card

Double – Triple Action
Games 1, 2, 4, 6, 9 & 11 Pay Double
Games 3, 5, 7, 10 & 12 Pay Triple
Coverall $250 * $500 * $750 * $1,000
2nd Chance $125 * $250 * $375 * $500
3rd Chance $125 Blue & Red $250 Green & Tan

Regular Pay
Coverall $250 Blue & Red $500 Green & Tan
2nd Chance: $125 Blue & Red $250 Green & Tan