Add your very own widget to your site. Just place this widget and copy paste the HTML you wanted to add.
This can be anything from YouTube vedio, Adsense advertisement, or sitewide anouncement.
This helps you to add custom HTML in your widget. So the posibility of this is not limited. You can do anything which can be done by using html and javascript.
These are some posible usage of this.
Placing adsense in your sidebar.
Making some anouncement to your users.
