As an update, this is what I've learned over the past 3 weeks:
Saphan Hin - the center of badminton on the island. The most competitive place to play but I've never been there yet as it's currently under renovation with an anticipated reopening date of Jan 2012.
Approximate Location:
http://maps.google.ca/maps?q=7.8636...97915&sspn=0.002035,0.004128&vpsrc=0&t=m&z=17
Andaman Badminton - good club with about 12 dedicated courts. Players vary from beginner to advanced. Must book a court to play (between 100-150 baht/hour) but if you're friendly you should be able to meet some other people to play with there.
Approximate location:
http://maps.google.ca/maps?q=7.877748,98.379811&num=1&vpsrc=6&t=m&z=19
Laguna Resort - Beautiful place and close to where I live too. I've been told they have courts there however after searching around online as well as physically going there and talking to three members of their staff, the only "badminton" they had was backyard badminton in the gardens. It's possible there was a language barrier but in talking to the competitive players I've met I haven't heard anything else about this place.
Approximate Location:
http://maps.google.ca/maps?q=Laguna...41,0.016512&vpsrc=0&hq=Laguna+Phuket&t=m&z=15
OTOP Private Courts - In talking to a guy at Superspots in Junceylon shopping mall and looking online, there are apparently some private courts at the rear of "OTOP Shopping Paradise". Haven't yet visited them or know anything else about them.
Approximate Location:
http://maps.google.ca/maps?q=Patong...radise&hnear=Kathu,+Phuket,+Thailand&t=m&z=17
There are at least two other clubs (JJ's and PIA) I've heard about but never visited nor know where they are. If anyone else has any info then please feel free to add it to this