@Ke***
actually that is a little incorrect,
it's NOT technically good for 9 months, a 6 month METV is ONLY valid for 6 months from the date it's issued, that's why it has that catchy name :P
BUT you can indeed get almost 9 months of stay out of it.
get the visa as close to when you enter thailand as you can
-enter get 60 days,
-when that runs out exit/re-enter get 60 more days
-when that runs out exit/re-enter get 60 more days
-just before the VISA expires exit/re-enter get 60 more days <- which takes you to 8 months and then get a 30 day extension on that last entry taking you to 9 months :)