[penetrator]

Cheers Tom. I'll most likely do Hat Yai after Langkawi/Penang then and miss the Malaysian invasion.

This is what I've read in a post from 2008 on Thaivisa about getting to Langkawi, does it sound about right ?

the cheapest and fastest way is to fly to Hat Yai, then take the Airport-Minivan going to downtown (was 80 Baht in early 2007, if I remember that right ). the Hat Yai Minivan station is not far from the airport on the way to downtown. hop off there (no matter what the driver may say), Minivans to Satun usually leave every 30 minutes or so.
if you go all the way downtown to the train-station, you will have to backtrack to the MiniVan-station again. if you arrive by train, a shared TukTuk (or charter it for a higher fee if you are in a hurry) to the Mini-van station usually leaves every 20-30 minutes from near the station (about 100 Meters to the left when leaving the station).
from HatYai to Satun the fare is 85-90 Baht (maybe increased now due to the fuel price hikes lately). make sure u tell the driver u want to go all the way down to the THAMMALANG ferry pier in Satun, which is about 8 km south of town.
from Satun, the ferry ride was 380 Baht in early 2007. took less than 2 hours if I remember that right....