welcome to the club bro...
i think u can go to koh lipe, an island just above langkawi but belong to thailand. it is 42km (23 nautical miles) from telaga harbour langkawi. u can take speed boat from telaga harbour for RM248 (2ways) the journey is around 1 hours. u can have ur passport stamp at koh lipe, near bundhaya resort.
i have been there early dec 2011, stay & dive with forradiving.com, 3 dive a day for 2 days, charge around RM100 per dive with lunch on board of double decker ship - it is a big wooden boat (haha... not small wooden boat anyway), check their website www.forradiving.com or browse youtube for more info....koh lipe should be good from nov2011 until early may 2012....
Dive spot - Yong Hua Wreck at 30m-40m depth, greeted by yellow tail barracudda.
the soft coral garden at pakacem & stonehedge is splendid (what more can i say)

Thanks for the replies divers. Mamakpenang,  for $100 mr per dive, do you use your own dive gear? My main concern is showing up with short notice. I think ferry and dives are okay but wondering about  last minute accommodation. Anyways will contact forradiving.com for accommodation. Thanks

haha...narco was right, don't worry about accomodation, the food was nice & delicious but a little bit expensive, expect 100baht for seafood fried rice, 30-40baht for hot/ice drink, 50baht for roti canai, koh lipe is far away from the main land.
u can dive with your own equipments, or with dive centre/rental equipments for another additional 400-500baht for 1 day, 3 dives.
if u stay with forradiving.com & dive with them, they give u 25% discount on the room/bungalow on the day u dive with them.
happy holiday & enjoy your diving.....

Welkam to MUW!