jQuery is a very good and a awesome plugin for all web developers and blog developers but there is most important thing is we have to and we should have to use it in a positive manner otherwise that could be harmful for our blog and website.
This plugin is very awesome and also very important for our blogs and most important for those blog who shows the videos on their blogs, you can easily turn off lights of your blog and easily can see those videos and feel like you are watching them in cinema halls ;)