According to a report in the New York Times, he had begun receiving small donations from people over the internet to pay the bill until Big Brother shut that down:
"The donations began pouring in on Thursday, many of them delivered electronically and accompanied by politically tinged comments. “You helped them to design the Bird’s Nest, but they sent you into a bird cage,” said one donor, referring to Mr. Ai’s role in designing the Olympic stadium in Beijing. “You charged them fees, but now they fine you more than hundreds of times that in blood and sweat.'"Most recently people have begun walking past his property in Beijing and floating paper Maos over the wall into his garden.
How To Make Flying Money:
First, tape a couple of high denomination Yuan together, then follow the instructions above.
Ai Weiwei will be waiting for you.
Update 2/19/2016: I don't know if the situation for Weiwei in China has changed, but here in the U.S., the website Artsy has a dedicated Ai Weiwei page which includes his bio, pictures of over 120 of his works, exclusive articles, and up-to-date exhibition listings.
You may also want to follow Ai Weiwei on Instagram @aiww where he has been chronicling the plight of refugees coming into Greece by boat.