That looks like it comes from some old sorcery book.

Ditto. And is too high and narrow to sit comfortably next to figures.

there is such a beast already. It's called a 'generic currency symbol'

http://www.fileformat.info/info/unicode/char/a4/index.htm

Great and apt comments.

>some old sorcery book

Is there something more similar than the Monas Hieroglyphica of John Dee, or a spoke of the "Helm of Awe"? Also, there is something similar in St. John's manuscript.

>And is too high and narrow to sit comfortably next to figures.

I agree from the outset.

>What about a circle (i.e. the world) with a vertical line (or two) going through it?

Something along those lines might do. Wouldn't the circle with horizontal strikethroughs look too much like theta though? What about a capital G (for globe) with either two horizontal or two vertical lines going through it?

A line or two parallel lines through something is the common element that says "this is a currency symbol." A new global currency would be best represented by something simple and easy to write quickly. (So, not a totem pole made of most other symbols, sorry.) I'd say a circle (for the globe) with two vertical lines through it. Allow for as much variance as the dollar sign has (just one line sometimes, break the lines to leave the inside uncrossed, make it a tiny superscript on a stick, whatever) or more (horizontal lines, why not). A closed phi ϕ could be used wherever encoding hasn't caught up — or indeed the generic ¤ since it's not far from the idea and isn't being used for much else. It would always be placed at the start of the number, like the dollar and pound, because then, if it happens to look too much like a stroked zero, it won't change the number.

Edit: I left the computer and Hrant got in before I hit Post — agreeing independent conclusions make it clear how self-evident this answer is.

Edit 2: Goodness, no, not the power symbol! In whatever future this is supposed to take place, you'd want a clear distinction between "on/off" (touching this starts the thingy) and "pay now" (touching this will cost you money).

cerulean: "A closed phi ϕ could be used wherever encoding hasn't caught up"

If you put that in italics, it would look like the mathematical symbol that stands for "null".

hrant: "we could just wait for the Renminbi"

Will there be a difference between the symbols for Renminbi and Yen?

> Will there be a difference between the symbols for Renminbi and Yen?

I hope so - the Yen is so 80s.

BTW, the Yen-like symbol in China's case stands for Yuan. Yes, it's confusing. The good news (as John H once pointed out) is that formally currencies are always indicated with 3-letter strings (and the Chinese one is RMB).

hhp

Not exactly on topic, but I find a lot of the currency design here inspiring.

http://richardsmith.posterous.com/

@Té Rowan:
That said, there is such a beast already.

Not quite. The symbol which you describe needs to be followed by the name of a currency to create a symbol for that currency.

So it isn't the same as a symbol which by itself is the symbol for one particular currency, the World Currency.

Ah, the explains the British Pound.

hhp