Who are the richest people in the world? Here's our listing of the current top 10:

1. Bill Gates (estimated at $90 billion)

Anyone on the planet not heard of the man who founded Microsoft with Paul Allen?

2. Warren Buffet (estimated at $36 billion)

The investment expert who's utterings are rarely ignored.

3. Paul Allen (estimated at $30 billion)

The other half of the original Microsoft duo. Now also known for his investment in American sports.

4. Sultan of Brunei (estimated at $30 billion)

Having attended Sandhurst Military Academy in the UK, the Sultan's wealth largely stems from oil and investments.

5. King Fahd Bin Abdulaziz Alsaud (estimated at $28 billion)

The ruler of Saudi Arabia inherited his wealth and position.

6. Sheikh Zayed Bin Sultan Al Nahyan (estimated at $20 billion)

Another example of the money to be made from the oil industry - this time in Abu Dhabi.

7. Steve Ballmer (estimated at $19.5 billion)

The current CEO of Microsoft - the 3rd Microsoft billionaire on the list.

8. Amir Jaber Al-Ahmed Al-Jaber Alsabah (estimated at $17 billion)

May also have one of the world's longest names! Money made in Kuwait, largely from oil.

9. Phil Anschutz (estimated at $16.5 billion)

Inherited a large sum and has subsequently invested in a range of industries.

10. Michael Dell (estimated at $16 billion)

You'll probably recognise the surname - the founder of Dell Computers.