These are just a list of Mozilla Firefox extensions I use on my box
1) Abduction: Right click on any webpage and "save page as" an image, a complete / part of a webpage.
homepage: https://addons.mozilla.org/en-US/firefox/addon/abduction/?src=api
2) Downloadhelper: Downloadhelper can capture images and files from soooo sooooo many sites.
homepage: http://www.downloadhelper.net/install.php
3) ABP: AdBlockPlus - ban/block those anonying adverts into oblivion.
homepage: https://adblockplus.org/en/firefox
4) AnonymoX: if sometimes you might want to relish in "invisibility", this is just right for you
homepage: http://www.anonymox.net/en
5) FoxClocks: provides a neat clock display just below your browser
homepage: http://foxclocks.org/ ex: below
6) Wappalyzer: if you are always as curious as I am when I arrive at a webpage and wonder: "how did they do that?", wappalyzer provides details of what web-technologies are used.
homepage: http://wappalyzer.com/
7) Web Developer: speaks for itself. Its a tool every web developer must have.
homepage: http://chrispederick.com/work/web-developer/
8) Torrent Finder Toolbar: provides a nice way to search for torrents from your browser
homepage: http://torrent-finder.info/
9) IP address and Domain Information: just in case you like sniffing around, this tool provides the geolocation, DNS, whois details, routing, hosting, domain neighbors, etc., as well as your own public(LIVE) IP address.
homepage: http://www.tcpiputils.com/
10) Download Youtube Videos as MP4: does this need any further explanation?
homepage:http://userscripts.org/scripts/show/25105