Macroscript that you can assign to a hotkey (I replaced 'C' with it) which cycles through your cameras each time you press it. Will jump to a camera if you have that camera selected. Works with BCams.
To install - copy into scriptsstartup - restart max - and select it from within Customise UI - in the cameras section.
Standard Maxsripts (.ms) can be run from the Maxscript button in the utilities panel. To have them always available - save the scripts into your scripts/startup directory.
Macroscripts (.mcr) can be placed in either scripts/startup or UI/Macroscripts - and are then accessed through the 'Customise User Interface' menu in 3dsmax. You can then assign the script to a keystroke - or a button. All macroscripts will appear under the 'Dusk' category in the dropdown.