IMGV

IMGV is a powerful, free and open source, Image Viewer that tries to do what other image viewers cannot. It can run on most versions of Microsoft Windows and Unix systems (Linux, FreeBSD, Mac OS X, and others)

Written completely in Python it's amazingly versatile.
It can run on Windows, OS X, Linux, BSD, and more.

The project was started in 2001 by Ryan Kulla.

This reminds me of a very old image viewer I used to use when we had MS-DOS. I tried it out and its very nifty and neat. Wonder now when we have so much of the GUI (Graphical User Interface ) thrown onto us how did the developer come up with something like this which looks so simple and uncluttered. Well its small and best of all displays your images fast.
Supported Files: JPEG, GIF, PNG, TIFF, BMP, PCX, TGA, PPM, PNM, PBM, PGM, XPM, XCF, LBM, IFF, MPEG
MPEG support means you can watch video (movies in this format) too. And if you really want all those options which you think is needed other than just displaying the images then a right click is to be clicked ;)

I had mentioned about Cornice before and yes you may compare them both. I still will like IMGV! (Wonder what IMGV stands for?)