Torrent Finder Toolbar is a torrent search toolbar for Firefox, which enables users to search over 170 top torrent sites and trackers from their Firefox browser the same way they used to search using www.torrent-finder.com form.

It allows users to search a single site, search all sites on one page, or open the sites in Firefox tabs.
A lot of accessible tools have been added to the Toolbar to make it easy to find your torrent like ‘keyword highlighter’, ’select toggle’ to toggle between search engines by category, and ‘toggle by first letter’ to easily find the search engine you need.
Torrent Finder Toolbar (...)

deliGoo is an extension for Firefox (2.0+), which is built into your browser in the form of an additional button on the tools’ panel.

deliGoo searches on the sites, indicated in your del.icio.us bookmarks. With its help you can find the necessary page according to any phrase or word, which it contains.

And one more thing – deliGoo can create on your demand custom search engines on any del.icio.us tag.
deliGoo - Delicious (del.icio.us) Search Engine (...)

CustomizeGoogle is a Firefox extension that enhance Google search results by adding extra information (like links to Yahoo, Ask.com, MSN etc) and removing unwanted information (like ads and spam).

All features are optional and easily configured.
CustomizeGoogle (...)