Geotagging with an iPhone 3G or 3GS
Earlier in the year I explained how you could use a little device to geotag photos for use with iPhoto. Last week when I upgraded my first generation iPhone to the new 3GS, I realized a much easier way to accomplish the same thing.
If you have an iPhone 3G or 3GS you can very easily geotag photos in iPhoto. Make sure you have “Location Services” turned on (iPhone settings under “general”) and then, while you’re out taking pictures, just take one with your iPhone camera. Using the built in GPS, the picture you take will be properly geotagged.

Just two simple steps. No extra software needed.
When you get back to your computer and are uploading everything into iPhoto, ⌘-click on the picture taken with your iPhone and select “Copy.” Then, select all of the picture you took with your other, non-GPS camera, and then ⌘-click and select “Paste Location.” All of your photos will be automatically geotagged and be available on the “Places” map in iPhoto.
It’s that simple.