(There's no video for SwitchRes 2 yet. Please contribute to MR and add a video now!)
SwitchRes 2 is a little utility that allowed you to switch the resolution of all your monitors (before MacOS X). You can access to all the resolutions of all your displays in a simple, customizable menu. SwitchRes 2 incorporates features from the Monitor Resolution, Monitor BitDepth, and Video Mirroring Control Strip Modules bundled with your system. You can use its menu in the Menu Bar, use its provided Control Strip Module, or click on the Finder Desktop with its Contextual Menu Plugin.
The utility was shareware but now it is free to use for everybody, using this license key as stated on the website https://www.madrau.com/SRXv3/html/SR2/shareware.html :
SwitchRes_2_5_3_.sit (461.18 KiB / 472.25 KB)
/ compressed w/ Stuffit
Emulating this? It should run fine under: SheepShaver