Image resize program

Does anyone know of a program that will allow me to load up a buttload of images and resize them all at once. I have a ton of screenshots for a shrine, and I really don’t want to have to resize them one by one. Thanks!

I know I have an option in Windows XP to mass-convert picture files when I right click them. But I can’t remember if it was a default option, or added with some program I installed.
GIMP? PhotoShop LE? … Kodak EasyShare?

Photoshop’s what I use. All the free trials are full trials, as far as I know.

I actually figured out that Irfanview can do that, which is a program I already had and used regularly, anyway. Thanks anyway, though.