Here is a link for a very efficient online photo resizer - Resizer

Instructions

1- Click the link to run the resizer program.
2- Select the photo to resize. You can "drag and drop" or click "Browse" to select the photo from your computer. Click the photo to select it and click "open" to use it.
3- On the next screen, enter the size wanted at menu item "4", "enter Max Filesize". Click "I'm done".
4- Click "View image" to review the new photo, then click "save to disk" to save the resized image.