Hell Money.

The Chinese believes that after someone dies, his (or her) spirit goes to the afterlife, where it lives on pretty much like in real life. And so just like in real life, you’ll need money in the afterlife - lots of it.

So how does one get money in the afterlife? Through surviving relatives and friends, of course, who burn these "hell" banknotes or money to send it through (probably because Western Union has yet to open a branch in the afterlife).

The afterlife probably has one hell of an inflation problem - the denomination on these banknotes are huge! This one above is a $8 billion note (the number 8 is considered quite lucky in Chinese culture).

But why "hell" money? Apparently, this maybe a simple confusion in the English translation. The chinese probably simply meant "afterlife".

BigWhiteGuy, a blog by Randall J. van der Woning, a white guy living in Hong Kong, has more fascinating details on Hell Money: Link