Off to Koh Samui for a bucket and spade holiday, and idly wondering if there was any climbing (or even bouldering) worth packing a harness and boots for (this of course also presupposes a local climbing school or other "hookup" scene)? A quick google doesn't come up with much, apart from a ghastly looking granite wall with literally bolted on holds, so I am guessing I am a little way away from the Yes album cover style limestone islands? As you can see, haven't done a lot of research yet!
There's a tiny bit on Koh Pangnan that's documented but its not far to Koh Tao which is a mecca for bouldering, and there's a good bit of sport climbing (and a tiny bit of trad, but loads of potential). I worked there for about a year and we bolted loads of routes including the islands first (small) multipitch. Check out goodtime adventures as they have a free downloadable topo map.
If you can't make it there, I'd still bring your shoes and chalk bag as all three islands are granite and there's bound to be a bit of exposed rock on Samui if you explore far enough away from the main centres.