Did you look at other currency signs? The EUR sign is an round E with two horizontal bars. The JPY symbol is a Y with two horizontal bars. The GBP sign is a curved L with one originally, but nowadays, in many fonts, two horizontal bars. The dollar, too had one vertical bar. Nowadays it has two, in many fonts. There is another dozen currencies with symbols following this logic. Do a google image search with "currency symbol" as the term.

Guess why?

Designers of currency symbols have silently agreed to use two bars to mean just that: "this symbol represents a currency". So the B with two bars, for Bitcoin, is perfect.

The real solution (that may need a website too, to advertise it to the masses, least not the peeps @ HN) is obviously to agree on some free unicode slot to occupy and to get font designers to incorporate this two bar 'B' into existing fonts, in this slot.

>The dollar, too had one vertical bar. Nowadays it has two, in many fonts.

That is not correct. There was not a transition from "two vertical bars" to "one vertical bar" [1]. Please document yourself before posting.

[1] http://en.wikipedia.org/wiki/Dollar_sign#Origin

I do not know what you mean by "document". I studied typography and designed digital type, for a while, about 20 years ago. So I know a bit about the design side of things. And the design side is what my post is limited to. I am sorry if this was a tad ambiguous.

I did not talk about the history. I talked about a typographical design trend that pertains to currency symbols. Also not that better typefaces sometimes have both versions on the $ sign. One and two strokes. The default is admittedly still the single bar one though.

Expert discussion re. the one bar/two bar $ sign, that could be an interesting read: http://www.typophile.com/node/17976

There's a very tight similarity: They're both currencies. Any icon for Bitcoin needs to communicate "I am a currency." Taking design elements from the dollar sign and Euro sign (the double bar through the middle) seems like a great way to do that.

Double bar is a great way to indicate currency? Dollar is often used with a single bar, just as pound, franc etc. See https://en.wikipedia.org/wiki/File:Currency-Symbol_Regions_o...

Oh, good lord. Let's just agree to use "💩". Problem solved.