Just a heads up, while Jing is still free it looks like it's time is coming close to where you will have to purchase it. It is now being offered by TechSmith and will have updates, etc etc.
I sniff a back-story here. When Jing started you had to host with TechSmith's screencast.com. Above any real level of interest, you needed a paid account. I still have mine which I use to deliver tech support for Yacapaca, and I'm very pleased with the service and value for money that I get.
At some point, TechSmith decided to allow users to download their Jing screencasts, which meant they could host them anywhere. This must be hurting their previously-guaranteed source of revenue. Hence the decision to move towards premium features. I must admit I will be a little disgruntled if I have to pay twice, but in the end it's a great product and I appreciate they cannot develop it without some secure source of income.