We have been posting about several Screencasting tools, we also posted a comparison of two twitter based Screencasting tools.
Here is another online solution to create screencasts instantaneously without installing any software.
Screencast-o-matic is a simple online tool, which allows you to create screencasts and later you can download it or upload it to Screencast-o-matic or on YouTube as well.
Once on the Screencast-o-matic homepage, all you have to do is, simply hit the create button, and allow the script to run, soon the recording window will appear in front of you, resize and move it to the desired area. Apart from this you can also choose the resolution and microphone settings as shown below.
Now once done with settings hit the red button to start recording, later you can either choose to download or upload it to YouTube or Screencast-o-matic server.
Screencasts can be downloaded in AVI, Mp4 and FLV formats.
So go ahead and give it a try, and share your experiences with us.