!Remove Start Page Advert Snippet
Firefox 4 and before:

# Goto C:\Users\Intersult\AppData\Roaming\Mozilla\Firefox\Profiles\8n2fqkg1.default\chrome
# Copy userContent-example.css to userContent.css
# Add #snippets {display: none !important;}
# Restart

With Firefox 5 or 6 \chrome has been removed:

# Goto C:\Users\Intersult\AppData\Roaming\Mozilla\Firefox\Profiles\8n2fqkg1.default
# Create folder \chrome
# Create file userContent.css inside chrome
# Add #snippetContainer {display: none !important;}
# Restart

!Plugins
* Adblock Plus
* Cookie Monster
* Deutsches Wörterbuch
* Download Helper
* Firebug
* Image Toolbar
* Image Zoom
* Java Console
* NoScript
* Password Exporter