• Install the Adobe SVG viewer 6 beta.
• Copy the NPSVG6.* files from C:\Program Files\Common Files\Adobe\SVG Viewer 6.0\Plugins to C:\Program Files\mozilla.org\Mozilla\Plugins (or $GeckoDir$\plugins) and restart the browser.
• Tada! You should have SVG.

Or as Phil said *phew*. Thanks Phil, foafnaut is just so much nicer to use from a proper browser.