2. AdBlock Plus – stop displaying annoying ads on websites
AdBlock Plus is, as its name suggests, an add-on which will strip all the ads from a website, very useful for those who don’t like ads put in unwanted places which can distract from reading and accessing a website properly. The first time it starts, AdBlock will prompt the user to select a country-specific list of advertising sites to block. These lists are huge and the end-result is very satisfactory.
Install from the Firefox add-ons page
Homepage

3. PDF Download – convert web pages to PDF
PDF Download is a nice, feature-rich add-on which will convert a web page to PDF on demand and it will save it on your hard drive. When you will select this action it will also open a new tab (or window, depending on the settings) with the homepage of PDF Download. This add-on also offers the possibility to specify the format of the PDF (portrait or landscape) and how to handle margins.
Install from the Firefox add-ons page
Homepage

4. Speed Dial – add-on similar to Opera’s speed dial
Speed Dial is similar with one good features the Opera browser ships by default. Speed Dial will display in a single tab several previews of web pages of your choice, which will make accessing your favourite websites faster and easier. The add-on allows you to set the number of rows and columns to be displayed. It is highly configurable via the Tools -> Add-ons menu option. The only drawback Speed Dial has is that for some sites the preview is not very accurate.
Install from the Firefox add-ons page
Homepage

5. Google Preview – insert previews in Google and Yahoo! searches
Yet another useful extension, Google Preview will insert previews in Google and Yahoo! search results, helping you to make an idea about what a specific site is about and if it is worth accessing it. You can set the number of maximum previews per page and and make it show the site rank in a small bar below the site’s description. Of course, it comes at bandwidth cost and a little slowness, but many find this add-on very useful.
Install from the Firefox add-ons page
Homepage