Sorry if something similar has been asked, had a rummage.
I'm going to be in Yunnan at the end of summer or beginning of autumn and will need to get to Bangkok from there to meet arriving friends. I can fly there no problems but a couple of people have told me about various shipping companies that ply the Mekhong from Yunnan to Thailand.
I'm told this doesn't require Lao or Burma visas as the boats don't stop until getting to Thailand.
If anyone can shed any light I'd be grateful.
I did a 2-day cargo boat ride from Jinghong to Chiang Saen a few years ago for 2000 Thai baht ($50 at the time) but the government has "prohibited" foreigners travelling this way in recent years. There are tourist boat services now though for about twice the money. See http://www.maekhongtravel.com or talk with the folks at Mei Mei Cafe in Jinghong who can hook you up with a boat. It may still be possible to stow away on a cargo boat but you may then have to cross the China border on foot and re-join the boat out of sight (dodgy). Other option is by regular bus from Jinghong to Mengla and the Boten border from which there is bus service 55km to Luang Namtha and continuing 198km to the Thai border at Huay Xai / Chiang Khong.
There is a daily bus from Jinghong to Huay Xai at 6:45 in the morning, it goes straight, no need to change bus at the border. Arrives around 16:30 to Huay Xai, just in time to cross the border to Chiang Khong . The price is around 120-130 yuan i think, the road is not bad at all, worse in the lao side. Jinghong and its surroundings is worth a few days btw (Menghai, ...). From Chiang Khong there are sleeper buses to Bangkok so you can finish the journey from Jinghong to Bangkok in 24 hours.
So the road from Jinghong to Mengla has been finished? When I went through in '07 it was a winding hill stretch in a minivan over roads that a regular size bus couldn't have made it through - as they were constructing what looked like a very nice highway. It took us something like 7 hours to get to the border.