milksama - that's exactly what I mean. WindowFX comes close: it has an option for CTRL-clicking, ALT-clicking etc. that will change windows to a preset resolution, but it applies to all windows. I want something like "right click top window border, and a drop-down appears that lists preset window resolutions, or an option to manually set the window's resolution". Combine that with the ability to snap windows to the screen edges (don't forget multiple monitor scenarios), and that'd be very helpful.
Picture having 8 or 9 PuTTy windows open: it'd be nice to be able to tile them, so to speak, and take advantage of a high-resolution monitor.
DanDaBear - Thanks for the link! I'll try that out.