ClickPic lets you quickly resize, rotate and flip images, and convert them from one format to another.
It has an incredibly handy batch image file renaming function, so you
can quickly give meaningful names to all those horribly-named files
that you get from your digital camera. And, if your camera records
orientation/rotation information, ClickPic can automatically rotate the
image to the correct orientation. And it does all of this from Windows
Explorer: