Making really big background images

For landscapes, seam carving methods (or content-aware image scaling) should work pretty well for resizing them, and obtaining background images in the right resolution for computer backgrounds is a common problem. What if your computer could scale an appropriate image for you, so that instead of plain scaling it did content-appropriate scaling? I might do that manually from now on rather than trying to find wallpaper in just the right size, since I have two monitors at work.

Mokalus of Borg

PS - My first attempts with the "Liquid Rescale" plugin for GIMP have been disappointing.
PPS - That might just be my general ineptitude with GIMP and the plugin.