I've used CAMTASIA for a while and it's a great tool for recording screen demo's, snaffling screen shots and recording nice youtube style screen scrapes of things your doing.

But wait! if you dont want to pay (and who does?) for the full product you can download Techsmiths excellent application called Jing, which is basically a Camtasia Lite, from here:

http://jingproject.com/

I use it for various short tutorials and screen shots of everything from technical setup instructions to simple in instructions to my mother-in-law on how to setup her email.

A few ways to use Jing

• Collaborate on a design project
• Share a snapshot of a document
• Narrate your vacation photos
• Capture that pesky bug in action
• Show your mother-in-law how to use download photos
• Comment verbally on students' homework
• Collect cool web designs or funny ads
• Post tidbits from your life on Twitter or Facebook

Personally I believe that Camtasia has a user friendly interface and although its quite easy to use, it has too many features that are just not required for someone that simply wants to record whats happening on their computer screen. You really need to play with it for hours to get to know almost all of its features.

I've been using Jing for a week now and it just, simply, works!

Try it out - you wont regret it.