There's really no better Mac OS X tool to resize or reduce the size of your photographs for uploading than GraphicConverter, a splendid shareware application that's been a Mac gem for years and years now. In fact, you probably already have it on your Mac if you look in the Applications folder. If not, pop over to VersionTracker and grab it, or go straight to the Lemkesoft site and download GraphicConverter.

Once you have GraphicConverter, open up your photograph and use the zoom menu on the lower left corner of the image to shrink things down by percentage until you get the size you seek. For example, here's one of my big photos at 13% size:

That's a good reduction for me, so I'm going to use that same percentage reduction and resize the image. This is accomplished by Picture -> Size... -> Scale..., which brings up this dialog box:

You can see the very first entry is a scale and one of the options is using "percentage" as a unit. That's what you want to do. Make sure you have "Keep Proportions" checked near the bottom, then type in "13" and click "OK".

A few seconds later, you'll notice that your image now shows "100%' on the lower left: you've shrunk down your picture!

Now choose File -> Save As... and give it a new name: don't overwrite your original large image!

That's about all there is to it. If you want, you can experiment with Sharpen Edges or Unsharpen Mask on the "Filters" menu as they often help your image appearance once you use an algorithmic reduction as we did.

Hope that helps you create more MySpace-friendly images on your Mac.