I've had a few times when I needed to create a video.

Two handy video creation services are:

 

Powtoon is a bit of work to understand but gives you tools to create very creative, animated videos.

 

http://www.powtoon.com

Screencast-o-matic is useful for when you want to record your desktop like you do when you need to create an instructional video.

http://screencast-o-matic.com/