TI-SmartView
This virtual calculator is very useful to scaffold learners in using TI-84 & TI-83+ calculators.

I use a projected image with a BlueTooth keyboard and mouse, handing control to learners, from wherever they're sitting. I prefer this setup to using an IWB.
SmartView-Calculator.png

The ability to record the keystrokes, and then insert them into instructional documents to support less confident users is very useful.
SmartView-Key_History.png