I have a new IBM T30 laptop, and it is very nice, but the video adapter has a strange quirk: it can support a ton of different resolutions, and for each of them, it can drive a monitor at lots of different refresh rates, except: the LCD's natural size (1400 × 1050), where it can only do 60Hz. Grr. This means that when using an external monitor, I have to choose a different resolution, or the monitor flickers.
So I switch resolutions when I switch displays, and my dispmode utility can do that, but now I have to also switch between refresh rates. So I added that to dispmode, and all is well.