How do you make fire from scratch?

Are you resourceful? How well do you estimate your own abilities? Does your experience match other's claims?

Outline

Pretend that you and the complete contents of your home have been transported to a desert island. A ship appears passing along the horizon but you haven't got a fire lit to make any signal. It is a dry sunny day. Can you start a fire in the time the ship takes to move across the horizon?

Detail

No you can't use matches, lighters, power tools or any other stored energy device.
Yes you can use anything found in the home. Perhaps carpet trimmings will do for tinder. I'll allow you as much wood as you like.
Guess: How long do you think it will take you? Half an hour? More, less?
I'll let you use an EMPTY cigarette lighter to get sparks. But NOT a straight magnifying glass.
You might try making a lens out of a lightbulb filled with water.
Bathroom chemicals are NOT a good source of energy.
If you have a manually powered dynamo (eg on a bicycle) then you can use that.
Compressed gasses are DANGEROUS and uncontrollable. Don't even consider using them.

The fun of this experiment is putting physics into practice. Ahem, not quite as easy as I thought. How many times do you try before giving up on one method to try another. How accurate were you with your time estimate?

Thought: Accidents will happen. As well as knowing the DOs and DONTs of first aid, often some improvisation is necessary; a splint for a leg or a lever to move a crushing weight. How can you LOOK at objects to evaluate their usefulness as something else?

Thought: You may have seen some method demonstrated on the TV and wondered why it was so difficult for you? Many of those demonstrations are secretly helped by deviousness and a lot of practice. Even then you only see the twentieth attempt that "worked" presented as the first. You can't launch a ship again and again for the cameras but you can declare things open many times, re-run races and even turn a peaceful protest into an angry confrontation until the director is satisfied.