
I applied the liquid resize Gimp plugin to the original 2816 x 2112 picture of me playing my electric guitar and told it to simply resize the pic to 800 x 200 and this was the result. Of course, the picture was probably too busy for the algorithm to figure out how it should approach this, and I gave it no guidelines as to what to preserve. Nonetheless, a very cool effect. I'll have to play with it with some more suitable pictures and when I get more time.
Thanks to Shamus Young and his commentors for directing me to this plugin. Watch the video there to see what the technology is actually supposed to do.
There's apparently also a Photoshop plugin available.