Have you ever wanted to download a Youtube video? This is very easy with Firefox as there is an add-on called 1-Click YouTube Video Download. Once you have installed this add-on there will be a link below every Youtube video where you can download them in the following formats: MP4 HD (High Definition), MP4 High-Quality and FLV.
Which format should I download?
This depends on what you want to do with it. The MP4 file format is usually the recommended format as it allows easy conversions to other formats. The FLV format is the container file format used to deliver video over the Internet using the Adobe Flash Player. Finally the 3GPP file format is mostly used on used on 3G mobile phones.