Back in the old days of Web 1.0, I would keep ZIP discs of programs because 56kps was just too slow to find them again.
From that time I used an image resizer program called JPEG Resizer. It had lots of features, was simple, fast and best of all free.
Thanks to Web 2.0 (is there anything it can't do) I now have a replacement called Pic Resize. You can upload single or multiple files, crop, resize by percentage or pixel and output as a jpeg, gif or png file. They have a few special effects like gray scale and rotate, just the basics.
Let me tell you, it sure beats trying to do resize a photo in MSN Paint.