Detects Duplicate Bookmarks when bookmarks are added and specify where is the previous URL. You can also search and delete duplicates URL already in your Bookmarks.

If you have a lot of bookmarks this extension is for you !

If you think it is difficult to find a bookmark within all of them then you need this extension. BookmarkDD add possibility to search string within bookmark’s location and bookmark’s description field.
See screenshots for list of options:
http://bookmarkdd.mozdev.org/screenshots.html

You can customize this extension with its configuration panel.
Bookmark Duplicate Detector (...)

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 (...)

FoxyTunes lets you control almost any media player and find lyrics, covers, videos, bios and much more with a click right from your browser.

Supports WinAmp, iTunes, Yahoo Music Engine, Pandora, foobar2000, Windows Media Player, Xbox Media Center, Musicmatch, Quintessential, J. River, jetAudio, XMPlay, MediaMonkey, Media Player Classic, Sonique, wxMusik, Real Player, XMMS, Noatun, Juk, Amarok, Music Player Daemon, Rhythmbox and many other players.
FoxyTunes (...)

Orbit Downloader, leader of download manager revolution, is devoted to new generation web (web2.0) downloading, such as video/music/streaming media from Myspace, YouTube, Imeem, Pandora, Rapidshare, support RTMP. And to make general downloading easier and faster.

Orbit Downloader supports HTTP/FTP/HTTPS/RTSP/MMS/RTMP protocols and provides a total solution to download rich media. So you can download music and video from social music/video websites including Pandora and YouTube more simply and easily.
Orbit Downloader (...)

SwitchProxy lets you manage and switch between multiple proxy configurations
quickly and easily. You can also use it as an anonymizer to protect your
computer from prying eyes. NOTE: In Firefox you can use the toolbar
element to save space
SwitchProxy Tool (...)

Download one link, selected links or all the links of a page together at the maximum speed with a single click, using the most popular, lightweight and reliable external download managers. Supported download tools are dozens, see http://flashgot.net for details. This extension offers also a Build Gallery functionality which helps to collect in a single page serial movies and images scattered on several pages, for easy and fast “download all”.
FlashGot (...)

With this toolbar you can access TOR-Proxy.NET directly. Hide your IP and surf anonymously. This Addon creates a new toolbar, where you can enter the address you want to take a look at.
It is easy to stay anonymous!
Tor-Proxy.NET Toolbar (...)

This extension display your current external IP address in the browsers statusbar.
External IP is set to check your IP address at browser startup and after that once every hour or on click on the right-click context menu.
external IP (...)