Administratively, Yunnan is divided into 16 prefectures. Some of those are autonomous prefectures for various ethnic groups. For the traveller, Yunnan can be divided into seven regions:
Its name literally means south of the clouds. The province is one of the most diverse in China. The Northwest of the province is heavily influenced by Tibet, with whom it shares a border. The South is influenced by its proximity to Laos and Burma. The province is famed for its multitude of ethnic groups, whose diverse customs can still be seen today. Of China's fifty-five officially recognized ethnic minorities, twenty-five can be found in Yunnan: about one-third of the population is not ethnic Han-Chinese.
The official language of Yunnan is Standard Chinese (or Putonghua as it is known). The region is home to a plethora of dialects from Chinese, Tibetan and Thai language families. Yunnan is home to many minority groups who each have their own different language.
Local towns will often have their own version of Mandarin which are sub-dialects of the South-Western dialect of Mandarin common to Yunnan, Guizhou and Sichuan. Despite a heavy accent, the local dialect of Chinese is very similar to Northern Mandarin with only minor regional differences in grammar and pronunciation.
Until 2003, Kunming was accessible by rail from Hanoi, Vietnam via a narrow-gauge railroad built by the French. The Chinese section of this rail route has since closed for passenger transport so the best way to get down to the border is by bus to Hekou (from where you can cross the border to Lao Cai and take the train to Hanoi), or by air from Kunming directly to Hanoi. One can take a train to Hanoi however via Nanning which is a safer option.
There is a railway from Hanoi to Nanning, Guangxi, and one with some sensational scenery from Nanning to Kunming. Another rail route reaches Kunming from central China via Guiyang, Guizhou, and a third one comes South to Kunming from Chengdu, Sichuan. All of these train routes offer spectacular scenery, with long stretches of bridges and tunnels.
Wujiaba Airport in Kunming is the biggest airport in Yunnan which is very near the urban, the taxi fare is about ¥12-30 if you want to go to any place of Kunming from the airport. Note that half way 2012 the old airport will be closed and the new airport "Kunming Changshui International Airport" will be used. The new airport is located 22 km outside the urban area and the subway to it will not be operational in time. So for the time being bus services will be used. Be aware of much longer travel times to and from the new airport.
Kunming has non-stop service from Beijing, Xiamen and other Chinese cities. There are also flights to Southeast Asia such as Seoul, Hanoi, Bangkok, Vientiane, Mandalay, Yangon, Dhaka. Laotian airlines and the consulate are both in the Camellia hotel, Kunming.
Bus, by thumb
There are multiple roads from Laos into Yunnan. It's not too hard to hitchhike, but it will take some time because of the often abyssmal road conditions and inept drivers. If coming from Luang Namtha, Laos, bus services are available to JingHong in Xishuangbanna, Yunnan. From Luang Prabang, Laos, a daily bus leaves at 7:00am for around 400,000 Lao kip. It arrives at the long distance bus station in Kunming very early in the morning the next day (around 5 or 6am depending on the driver). The road conditions on the Laos side both from Luang Namtha and Luang Prabang are at times sketchy and definitely mountainous to cause some people discomfort but get smoother on the China side and are much improved from awhile ago.
From Vietnam, the border crossing is from LaoCai, Vietnam, to HeKou, China. The rail route from HeKou to Kunming remains closed, so the only public transport option is by bus. The ride lasts roughly 10 hours, tickets cost around ¥135 and departure times are as following: 8:45am, 10:50am, 12:30pm, 1:00pm, 5:50pm, 5:55pm, 6:00pm, 6:05pm.
Golden Peacock Shipping company runs a speedboat three times a week on the Mekong river between Jinghong in southern Yunnan and Chiang Saen (Thailand). Passengers are not required to have visas for Laos or Myanmar, although the greater part of the trip is on the river bordering these countries. Be aware that shipping can be halted when the river levels are to high or to low which is often the case. Due to piracy the transport on the river was closed for some time in late 2011 and early 2012.
Everything and everywhere is accessible by bus from Kunming. Dali takes about four hours, Lijiang seven, Zhongdian twelve. Generally, the transport network is built as hub and spoke, so the easiest way of getting to a smaller place is to travel to next biggest town near it, change and maybe change again. You can now reach most larger towns in Yunnan by day bus. There are a lot of night bus services as well. There is a large collection of bus schedules, taken at bus stations all around the province, at .
Within Yunnan, there are planes to Jinghong, Dali, Lijiang, Zhongdian as well as lesser known destinations such as Dehong, Tengchong, Wenshan and Zhaotong. A new airport of interest to tourists is under construction at Lugu Lake.
Kunming is also the hub of train transport in Yunnan. Day and night trains now go both to Dali and Lijiang. Trains heading to east stops by Stone forest. Otherwise trains are of little importance to tourists inside the province.
Bicycle touring in Yunnan is a very good way to explore the local landscape and many cyclists from world have done this.The Dian-Zang highway(Yunnan Tibet highway) is one of the best cycling routes in China, and many cyclists gather together to explore the landscape and ethnic minority culture. You can hire bicycles in some cities, like Lijiang and Dali. It is possible to delivery your bike by train or bus. Yunnan Cycling  a local cycling website.
For the game of Go (Chinese: weiqi 围棋), the best Chinese stones are Yúnzǐ (云子), Yunnan stones. They are quite different from Japanese stones, and much cheaper. The flower and bird market in Kunming is a good place to pick up a set, and it is possible to visit the factory near Kunming. See the Yunzi article  on the go players' wiki, Sensei's Library.
All weapons confiscated by Customs. Keep Bags nearby in Public Places, Like everywhere else thieves can be a problem. Specially in night buses one should take care of ones belongings.