OK, Singapore is issueing multi entry Non imm "O" visas for married people which are valid for one year, yep married not for children, ie you got a kid and you aint married you aint gonna get this visa.
The 30 day on arrival visa will be strictly enforced, I had a little chat with the chappies on the Cambodian border today, the immigration there will not let you back in if you have done 90 days on VOA visas, they will warn you of this before you cross the border, thats as long as they catch it then I suppose, otherwise you maybe a tad foked, but if you come in on your third VOA you can then on your next visa run goto a Thai embassy or consulate and apply for a tourist visa and start it all again.