For most content, Sitecore has a dedicated Web Control that renders it: sc:Image, sc:Text, sc:Link, etc. But in many cases, something like sc:Currency would also be very convenient, for the rendering of prices. Sitecore has not yet provided a solution.
The solution at http://deceptacle.com/2011/07/07/sitecore-money-field/ is not sufficient, because it does not have Page Editor support: the output is not editable in the Page Editor. So we have to modify it a bit.