Must Have Firefox Addons

No Script: because it doesn't really matter if there's a hole in the newest  JavaScript  version for firebox. Link

Ad Block Plus: get rid of most nasty ads. Link

Cookie Monster: site cookies can store information on your browser about your preferences, but can also used to track you on the Internet.  Link

DTA (Download Them All): I'm not a mass downloader but this Addon is a must with Unplug. Link

Firebug: a must have for web hacking. Link

Lazarus: after typing 10 times the same form, you end up installing this.  Link

Skip Feedsportal: some RSS Feeds create a special formated url to keep a track of the sites you visit. If you don't want that, this Addon is for you. Link

Stylish: Check on my other posts to see what can you do with it. Link

Tabs on Bottom: as firefox user since version 1 I like the old style more than the new one. Link

Unplug: Extract media from web pages like Youtube. Link

User Agent Switcher: In some cases, if a web pages is acting weird, you can force them to believe you are using a different browser.  Link

A bit more anonymous way for Youtube browsing

If you use Google productos like blogger or gmail, you will notice that entering in Youtube automatically use your google credentials on the site. Which means all videos you search and browse are registered in your Google Account.

If you want to avoid that, you need Firefox and Cookie Monster. Once installed you will have a new Icon with the letters CM, go to youtube, click on the icon and select Cookie Access (site level) and select Reject Cookies. You will notice that even if you use gmail or blogger or even google it wont log you out from those sites.