Quote - I use IrfanView, it can resize, not immediately sure if it can batch process. Certainly worth a look.

It does batch processing and I use that feature all the time. Besides resizing, it can flip, rotate, crop, and change colors, gamma, sharpness, and a whole lot more in a batch process.

My visual indexes of Poser content are at http://www.sharecg.com/pf/rgagnon