Smells like burnt...

That's because the rituals of offering are BIG in Cambodia, and in all Asia for that matter. Whatever religion or creed around, there will always be offerings. In the Buddhist one in Cambodia, offerings are made in the form of fruits, burned incense sticks and money in pagodas, in front of the Buddha statues, or in the little genie houses in each one’s home. Oh, but do not worry, I forgot to mention that the money is not real. You can buy fake money to offer or burn:-)..
Yes, in religions like the Taoist one, the offerings are burned..Traditionally, it was joss paper made from bamboo, also known as ghost money, that was burned in traditional Chinese deity or ancestor worship ceremonies to ensure that deities or the spirits of the deceased have lots of good things in the afterlife. People think that money can be used in the afterlife as well, and that the ancestors can influence the fortune of the living. For me it is weird to notice this emphasis on the material side… But then again, I have to admit I don’t know much about the Asian religions and creeds, am only discovering now..
To illustrate the materialism behind it: nowadays people have modernized and burn from paper credit cards, cheques, to papier-mâché clothes, houses, cars, toiletries, and servants. And even more extreme, they burn paper MP3 players, planes, boats and even paper condoms (staying safe in the afterlife), paper prostitutes and Viagra …
Many temples have large furnaces outside the main gate to burn these offerings. Burning actual money is considered to be nonsensical (obviously!!) and unlucky in Asian cultures. These offerings can also be burned in front of ones house --> hence the strong smell of burnt on the streets.
The most interesting form of paper note that is burned in these rituals is the Hell Bank Note, which has a funny story. “Hell money notes is a modern form of spirit money. The word "hell" was said to be introduced to the Chinese by Christian missionaries. The missionaries told the Chinese that non-Christians go to hell when they die. The Chinese, not understanding what the missionaries were implying, translated the word "hell" to match the pre-existing Chinese concept of "underground hold/court," which in Taoist cosmology had been considered the initial destination of the soul of the dead regardless of his or her virtue during life. Hell money notes are known for their outrageous denominations ranging from $10,000 to $5,000,000,000. The bills feature an image of the Jade Emperor on the front and the "headquarters" of the Bank of Hell on the back.”(Wiki)

For me this is taking the bribe to another level .. :-)