If you have VISTA ( which I have, darn it)..the free auto-resizer doesn't work on Vista. I had to download a free program called VSO Image resizer. It works on both XP and Vista...by right clicking on the photo. It will do batch resizing too. I've only used it for a week or so, but so far, it works great.
http://www.vso-software.fr/products/image_resizer/