There are some really nice and simple gadgets available that give us teachers some good ability to move away from the front of the classroom (and not just be tethered to the computer).
The most essential tool I like to use is a Laser pointer which can cycle through your slides and animations on PowerPoint (or whatever application you use to show your presentations).
I like the Logitech PROFESSIONAL PRESENTER R800 as a good choice simply because the USB receiver plugs into the device when not in use which makes it a lot less likely to lose)
A second must for me is a Bluetooth speaker which can be used to broadcast sound to any point in the classroom. They might look small, but they are really loud and can be either:
I chose this one in particular because it has an Anodised Aluminium-Alloy case (and is rugged enough to withstand accidental knocks and drops), is small enough to fit in my bag. It also is compatible with devices with either bluetooth or a 3.5mm Jack and can be charged via a micro USB cable.
My tip is try to avoid any Bluetooth speaker where the soft speaker parts are exposed (as these may get damaged while be carried in your bag)
There are two different types of device:
The device on the left is a Netgear PTV3000 which allows the wireless transmission of your picture (and sound if you want to use the speakers on the projector but I much prefer to still use my bluetooth speakers). This device works for Windows machines and the Google Chrome devices but I would advise you to check it works for your particular devices before making a purchase and testing it out at home linked to your TV). I have found these work and are better for presentations (they can be very laggy when streaming video and that limits their usefulness for me at the moment).
The second device (on the right) is an Apple TV which works well for streaming iPads and Apple Computers to the projector. Again there are some lag issues when streaming video and some limitation as to how many devices appear in the device list on the iPad when choosing where to broadcast to) and this needs some careful network management (or use of Bluetooth discovery) to make sure teachers connect to the correct device in school environments that have many Apple TVs in use. Obviously, one limitation is that Apple TVs only work with with Apple Devices but never fear, Air Parrot 2 works really well to allow Windows devices to broadcast to multiple devices like Apple TV and Chromecast.
For other ideas for teaching in general and teaching aspects of Computer Science / ICT and Business, click here.