Vi Style Keybindings in Firefox
I'm very used to vi-style keybindings, particularly j/k for down/up, and I wanted them in firefox. There is an extension, vimperator that does this, but it also does a lot more - more than I want. Some more searching turned up keyconfig, a firefox extension that lets you configure arbitrary keybindings. Perfect! I'm using the extension, along with the following in prefs.js to have j/k bound to scroll down one line / scroll up one line and J/K as page down / page up.
user_pref("keyconfig.global.20080929", "");
user_pref("keyconfig.main.xxx_key__Page Down", "shift][J][][goDoCommand('cmd_scrollPageDown');");
user_pref("keyconfig.main.xxx_key__Page Up", "shift][K][][goDoCommand('cmd_scrollPageUp');");
user_pref("keyconfig.main.xxx_key__Scroll Line Down", "][J][][goDoCommand('cmd_scrollLineDown');");
user_pref("keyconfig.main.xxx_key__Scroll Line Up", "][K][][goDoCommand('cmd_scrollLineUp');");