Copy Plain Text 2 - a nice extension
How to install bytubed
YouTube Anywhere Player - a must have extension !

S3.Google Translator

S3.Google Translator S3.Google translator translates the selected text, the introduction of any phrases or all web-site from any language to Russian

Detailded description:

S3.Google Translator is an addition to browser Firefox, which will make your visit will not Russian sites.   Simply click it to create your very own invites to the event! The Organizer even works with Google Mail
  ClockIt.In Firefox toolbar extension
Supplement based on the public interface of translate.google.com / and therefore has at its disposal more than 50 languages, from which you can make the translation into Russian. Also enables auto-detection and the original language.   The button switches on/off 3 following preferences within content of browser's option:
  Youcan uninstall from add-ons Manager
The current version of one-way transfer: from any language to Russian.   QUICK HOWTO: Just press F11 to go full screen (Cmd-Shift-F on Mac)
  ChromaTabs Plus makes tabs more readily
Firefox add-ons in the pantry has many unique, simple and complex, but they all have one annoying feature: the translation of the selected text text formatting is lost. We S3.Google deprived of this trouble, and I hope you will be very useful.   "Web Search") and ones created by other extensions
  Save videos from any video host to your
Web-page supplement: www.s3blog.org/s3gt.html   Links can include tag and label as particu
  You can change these behavior by an opti
  Import bookmarks to your FavSync page ma
New in version 1.14:   When you first install the extension, yo
  Write a review and win Motorola RAZR i (