From the quick and dirty tools category, FastStone image tools work well and don't ask many questions. There is the Image Viewer (which is a browser, image editor, and converter), Capture (a screen capture utility that captures almost everything on screen, even flash), MaxView (a image viewer), and Photo Resizer (a batch converter, renamer, resizer). I use both the Capture application and sometimes resizer when I have a lot of pictures all at once that I want to convert or rename. They aren't by any means Adobe quality picture tools, but they work fine, and the are cheap too. You can't get much cheaper than free.