How can you make a US passport photo 600x600 pixels and no more than 240 KB for immigration purposes?

This solution is for people with Windows computers. Not overly technical, but it worked for me. You will need Windows Live Photo Gallery (comes with most modern computers or download it, and download Picasa (google it)

1. First you need to make your photo a square. Open your photo with Windows Live Photo Gallery (Click on Windows symbol in bottom left of screen, click on All Programs and click on the file, or search for it if you use Vista.)
2. Find your photo in Windows Live Photo Gallery (all your computer files will be on left side of program).
3. Double click on photo.
4. You will see a range of photo editing options on right side of screen. Click on "Crop Photo."
5. You will then see something saying "Proportional" and a click-down list under that. Select "Square" from the click-down list.
6. A square will appear superimposed over your photo. You can make the square bigger or smaller by hovering your mouse over one of the corners of the square. You can also move the square around. Size and locate the square so that the head and shoulders remain in the photo.
7. Click "Apply" under the click-down list on the right hand side.
8. Close Windows Live Photo Gallery.
9. Open Picasa.
10. Locate your photo and double click on it.
11. Click on "Export" which is on a task bar directly under your photo in the program.
12. A pop-up will appear. Choose where you want to save the photo (make it somewhere you can find it).
13. The pop-up will also have options to "Use original size" or "Resize to." Click on the "Resize to" option.
14. A box with "pixels" written beside it and a sliding bar can be seen under the "Resize to" option. Type "600" into the box.
15. Click "Export".
16. Your photo should now be ready to use. Go to the Immigration Photo Validator webpage (google it), and check your photo. It should come back with "Your photo is valid."
17. Click "apply.

Another way:

Download Irfanview. It will do the job.

Resizing the picture in Irfanview ,

Click the file tab,

click open to import the image,

click image tab,

click Resize/Resample,

select new size as 600x600,

Disable aspect ratio,

Press ok.

click on File,

click save as, to save the image/picture.