By default, there is no easy way to resize multiple images.
Example:
Bob has a folder of images he wants to resize, currently in order to do this he would have to open up and resize each individual image, aka, a PAIN.
Thank you for that! I'll be using it. But I think a program with a GUI would be better for noobs. Also if you could specifically have it put the resized pics in a different folder, so you can save your high-res ones, that would be great.
Try nautilus-image-converter. It adds right-click options to images in Nautilus. You can select all the images in a directory and then right-click to rotate or resize.