Tired of waiting for Photoshop to load just to resize an image? Worried about giving up precious memory to a non-CAD application? Enjoy lightweight, high-performance mini-applications? You should use IrfanView.
Free download, extremely small footprint (opens instantly on even the slowest machines), lots of useful features. Resize, rotate, crop, save as another format, batch processing, slide shows… And everything has a shortcut key. It’s so fast you use just S for Save-As, not Ctrl-Shift-S.
One of my favorite tools. Go get it.