Firefox extensions for JS disabling and Python integration

My collection of Firefox extensions is mostly just the usual stuff you need for web development, such as Firebug, MeasureIt, ColorZilla, S3Fox, FlashSwitcher and a few more. After Firebug, for long time I didn't spot anything comparable spectacular. But recently I discovered some interesting extensions:

• QuickJava: Finally an extension which makes it dead simple to disable/re-enable Javascript (I use that often to see how Ajax enriched webpages look like without Javascript). Just one click on a status bar button to enable/disable and reloading the page. Here there is even room for improvement: I would like to have enabling/disabling optionally coupled with reloading. Anyway, other extensions which provide the same functionality require a lot more GUI interaction.
• Pyxpcomext: Python bindings (PyXPCOM). This extension doesn't provide any direct end user functionality, but makes it possible to write extensions in Python instead of Javascript. Just for fun I installed the Python Shell. I can think of many potential use cases, e.g. integration with the Python based App Engine SDK, so that web designers not comfortable with command line interfaces could easily interact with the local App Engine test webserver via such an extension, when testing their templates and stylesheets.