You can customize autofill and keyboard shortcuts of script. You have to edit the script after it is installed, but it includes the functions that are used and you only have to call those functions.

Blocks the body.onclick event. Some web-pages use this to circumvent the popup blocker built in to Firefox.

Makes frames resizable, all borders visible, and scrolling if necessary

Removes accesskey attribute from tags if they are set to f,e,v,g,b,t,h,d,a

Google directory links redirect to DMOZ. If a Google directory page is navigated to, it uses DMOZ instead.

This script makes image alt text appear in tooltips when the mouse hovered over it.

Blocks inline popups, that appear in the same window and that scroll with the page. Now everything based on scrolling is blocked.