You've inpsired me!
In Firefox:
LocalStorage - about:config Dom.storage.enabled
Canvas - block JS via noscript
DRM - Preferences->Disable DRM content checkbox
WebRTC - about:config media.peerconnection.enabled;
As a side note, noscript has been an eye-opener for how many things are loaded when I open anywebsite! It's been fast, but I've been getting annoyed by guessing what to enable to move past a blank webpage.
And WTF is newrelic and why does half of my internet browsing use it?