I started porting Galeon's "Page Info" dialog to an Epiphany extension. Crispin (the Great Galeon Hacker) helped me understand a couple of details, and Christian (the Great Epiphany Hacker) persuaded me to make the "General" tab look nicer.
I used to hate Glade (its UI is pretty lousy), but I think I'm getting used to it now.
Anyway, Christian restructured it after I'd ported over "General" and "Images". Then I added "Links". So the extension has 3 of 5 tabs now. Not bad for about 10 man-hours of work.
The Page Info extension will most likely be in epiphany-extensions 1.4.0, which will be released in sync with Epiphany 1.4.0. Rockin'.
Even cooler, though, is the patch I've got which lets you load/unload extensions as Epiphany is running. There's no UI frontend (it uses GConf) and I coded it way too late for 1.4.0. But it's gonna be great: in 1.6.0, the user can specify which extensions to load. Now... if only Marco would review it!