The Forecast Plus Firefox Plugin: http://add0n.com/forecast-plus.html
Most functionality generally works. The main forecast page comes up. Some subtabs, like "Rain/Snow" hang with a spinning icon because of:
http://icons.wxug.com/scripts/wui-precip/0.1.1/wui.precip.min.js
This gets blocked by default.action's rather blunt
/recips?/
Putting in a user.action exception for:
icons.wxug.com/scripts/.precip/..js
appears to restore the plugin's full functionality.