one of themost important widgetsfo blogger is the "youtube vedeos search " widget. it is free and have  an esthetic impact on your blog also it would simply help you to search for vedeos from you own blog istead of searching about it in youtube.

you can simply add this widget to your blog just go tou your blog and click on ad widget and chose "javascript" then put this code and congratulations

<iframe scrolling="no" frameborder="0" width="102" src="http://search-youtube.blogspot.com" height="114"></iframe>