You never know what you'll find on tech gadget sites.

Solar Spark Lighter

It won't fit in the Altoids tin.....

Sue

you can also use the reflector from a large flash light.

Possibly useful to store for any long term emergency in which matches or lighters may be in short supply.
Would appear to be of limited use for camping or most emergencies, since a fire is of course more likely to be needed when it is cold, wet, and lacking sunlight.
One could light a fire in sunlight, and keep it going until dark, but that would need a lot of fuel.

Useful for smokers since during sunlight it would save expending a match for each cigarete.

A nice fire is also quit useful in scorching hot weather e.g. to cure water and cook food.

You can also polish a pop can with a piece of chocolate too. Of course you need to have both.

Fresnel lens is the most ultimate solar fire starter alternative known to men. The best ones could be salvaged from an old portable overhead projectors.

I´d rather eat the chocolate than using it to polish a can...

I have been known to buy cheap glass magnifiers.
Not only good for reading fine print but effective paper weights too.
Yes, they could light a fire but I usually have lighters and sparkers with me.

Your parabola mirror thing is a bit of cool bling though.

Should have added never eat the chocolate after using in this manner. I'm sure everyone here knows that, but someone with no common sense you just never know. That's why we have all the don't do this in the instructions manuals now.