In reply to Rach G:
Definitely worth a trip to the Krabi area, if not Railay and Tonsai. There's now alot more to climbing in S. Thailand than Railay and Tonsai! You are correct in assuming that Railay and Tonsai will be totally rammed and fairly dirty. Easy enough to avoid the crowds though, as there is now plenty to do on the "mainland" away from the honeypot areas on the Phranang peninsula.
There is a fairly newly developed crag called Spirit Mountain in a small villae about 15 mins from Ao Nang/25 mins from Krabi. Plenty to keep most people busy for a week or so, and it's easy to take a day trip (or two) from there to climb at Tonsai/Railay. This way you get the best of both.
It might also be worth considering Koh Lao Liang - a small island down in Trang province. Again, it'd be easy to combine this with a trip to the Krabi area. About 2 hrs in a minivan from Krabi takes you to a small pier near Trang, then about 45 mins on a longtail out to the island.
Also consider Koh Yao Noi. Totally beautiful, quiet and unspoilt island with crags that are unlikely to get busy due to some "involved" approaches. You need to be comfortable riding a moped on dirt tracks etc to get the best out of it, but assuming you are: look up crags like "the Mitt". There are also crags that are accessible by boat - organised by the small climbing shop in the village on the island.
We spent 6 months out there this year and managed to avoid filth and crowds, so if you need any further info drop me an email.
