Does anyone know of any image resizing software that will batch re size pictures (Desktop Wallpaper) to popular screen resolutions.

I know there are tons of image re sizing programs out there but none that I can find will do what I want, I work with desktop wallpapers for all sorts of different screen resolutions and right at the moment I am doing this in Photoshop, one picture and one resolution at a time, this can be quite tedious work, especially these days with so many different screen resolutions.
What I am looking for is an image re sizing program that I can load one picture into, choose multiple resolutions and have the software spit out the same picture in multiple resolutions. Plain, simple and nothing fancy, software that will just save me tons of time.

I would prefer something that is free or in the worst case a fully functional trial for testing before purchasing.

Thanks in advance