Hello!
I am a web developer and logo designer. I know how important it is to have a logo that works in all sizes, including the small favicon format.
This is what I've made:

And in small sizes, it is still easily recognizable and readable.

It is made as a Scalable Vector image, like any good logo should be, and can be resized any way you want.
The .svg file can be seen here.What am I looking at?This is a logo that takes a style similar to the ones used for the Bitcoin, Litecoin and Namecoin. I decided to use the cyan/blue colour style you already use on the current worldcoinfoundation.org logo, because it fits the 'world' theme.
The logo takes the shape of a circular coin, with a shiny blue border and the face of the coin being a 'world' emphasized with latitudes and longitudes.
The white 'W' follows the lat/long lines, but also, this kind of bold sans-serif font emphasizes the fierceness of the coin. This logo is instantly identifiable between all other coin logos that exist to date, while being familiar to anyone seeing other cryptocurrencies before.