There are an unbelievable number of sites that provide streaming which can be accessed for classroom use as well as planning. YouTube is always a preferred favorite, as well as United Streaming, Discovery Channel and the History Channel. There are many wonderful videos on Netflix, but the district currently has that blocked from in-school use.
Flickr has a fun link for using images to spell words or titles which can be used on webpages and blogs. The site is http://metaatem.net/words and can be very fun to play with. I've used this on our family blog to post names of a family member who might be highlighted in that blogs' post.
Adding video clips is a nice touch to a blog or webpage. It gives an added "entertainment" that will keep the interest of the student and often be very helpful to provide added information for whatever the post may be trying to share.
The video above as well as the following "Bill Nye" clip are just two examples of what can be incorporated within a blog, used as a classroom warmup, or something with which to conclude a day's lesson.
Web Albums are useful when trying to give an assorted viewing of a concept. We kept a web album running last year in the right panel that would scroll through a collection of volcanoes. This was interesting for the students to see a continually changing collection of images that related to what we were talking about.