Free Open Source Software (FOSS) and Web2.0 that make technology accessible to students.
Very similar to teamviewer but uses a different back end remote method.
This is my first Choice in Remote Tech support. You can easily swap from watching/remote control to presenting your screen. Allows for file transfer an chatting. The free version does require both parties to download an exe file, but the file can be be ran standalone so no installation is required.