Three-Day China Visas
An increasing number of Chinese cities are introducing three-day (72 hour) visas.
Currently passport holders from 45 counties can travel to Guangzhou, Beijing and Shanghai visa-free assuming they are transiting to a third country.
Essentially the process is a transit visa process and is relatively paperwork friendly.
It is advisable to check the rule closely and ensure that your nationality/passport is eligible.
According to a recent article in the China Daily the country hosted 27,2 million foreign visitors in 2012.