In reply to Cragrat Rich:
Fly to Krabi. Stay at Chong Pli just outside Ao Nang...bungalows for about 400 THB right under the crag. Rent a moped and when you fancy a change from Chong Pli, do day trips over to Tonsai and/or Railay. Chong Pli is vertical to slightly overhanging and has some great techy routes that aren't typical of the super steep Thai climbing. On day trips over to Tonsai and Railay, I'd recommend focusing on the big, steep multi pitch routes. You can climb single pitch sport anywhere, but I think the multi pitch stuff is what sets Tonsai and Railay apart. I'd recommend kayaking over to Ao Nang tower to do orange chandeliers (6c), Humanality (6b+...busy but superb...go early or stay over in Tonsai for an early start). Then King Cat on Cat Wall, the Monitor on the Monitor Wall and almost any of the big routes on the Thaiwand. There are also some out of the way, newly developed crags on the "mainland" that aren't in the guide yet...Bat Cave and Naga, an easy moped ride from Chong Pli. People moan about the trash in Tonsai. There is an easy answer...don't stay there, but just take a boat over to climb. It'll cost a fiver return each time but given the lower cost of everything outside Tonsai/Railay/Ao Nang, it's also cheaper to stay in Chong Pli. People think they're getting some sort of authentic Thai experience in Tonsai and Railay, but they're not...for a more Thai experience stay somewhere outside Krabi or Ao Nang and visit the nearby markets in Ban Khao Klom and Klong Muang. There are also great rivers to swim in nearby etc, plus deserted beaches. None of these things are available in Tonsai.
Once you've done that for a week or so head over to Koh Yao Noi for a much less crowded and less polished single pitch experience, plus some great Thai culture. Rent a moped and ride from Ao Nang to Ao Thalane and get a local to help you carry your moped onto the ferry. Make sure you visit the Mitt and the Grateful Wall. Watch out for snakes...we had a close encounter with a cobra on the way up to the Mitt! Great adventure riding over on mopeds and saves messing around with Taxis etc. Just ride to the pier and catch the boat...
If you don't love Koh Yao enough to just spend the rest of your trip there, when you leave head a few hours south to Lao Liang. Possibly the most perfect sport climbing destination anywhere. Camping on the beach, 100m to the crag and access to DWS, single pitch, multi pitch, kayaking, snorkelling. All world class and a very chilled place. A few pics in my gallery somewhere I think.
If you need any further info drop me a mail. Can put you in touch with a friend who lives out there, who can book digs and arrange transport for you to make things a bit easier. He runs the resort on Lao Liang, so can sort that out too.
Enjoy...!