Qiewt is probably the tiniest, simplest image viewer out there. It displays any image thrown at it (i.e. dragged and dropped on it) on your desktop - just the picture, no borders, no frame, no toolbar.
Move it around with your mouse or keyboard. Scale it to different sizes. Read on for a complete feature list.
[li]Drag and drop any number of image files on Qiewt to display them[/li]
[li]Move the images around on your desktop by dragging them with your mouse or pixel-wise by means of your keyboard's arrow keys[/li]
[li]Scale the displayed image using your mouse wheel or the + and - keys[/li]
[li]Scale or move in bigger steps by holding the Ctrl key pressed[/li]
[li]Open images in new windows by pressing the Ctrl key while dropping the files on an existing Qiewt window[/li]
[li]Reset to original image size by pressing the middle mouse button or Esc[/li]
[li]Close Qiewt with Backspace[/li]
[li]Click with right mouse button to find out original and displayed size[/li]
[li]You can pass any number of image files on the command line[/li]
Now... what's it for?
Why, you may ask, do I need something that simple? Life is more complex than that!
Well, I don't know what uses you may come up with, but I do web design and I often need to have a quick look at whether some graphic fits into some existing web page or whether some image slices for page backgrounds fit well together. Without Qiewt I would have to take a screenshot of the webpage, open it in a graphics program, add the other graphic, etc.
Qiewt is written in Python using PyQt4. So everything you need is a recent version of Python, PyQt4 and Qt4 which are already included in every up-to-date Linux distribution.
To run Qiewt, just make sure the mentioned prerequisites are installed, download qiewt.py, make it executable, click on it (or something equivalent) and there you are!