UPDATE: New version of InfoPanel.nib file is now available that doesn't break Keywords. Thanks heaps IntrepidAntipodean!!!

Following up on our recent iPhoto geotagging discovery, we poked further still and found a way to enable the hidden feature.

By slightly modifying the InfoPanel.nib file inside the iPhoto bundle, we were able to unhide the Show button next to the GPS fields.

How to do it?

If you have XCode installed:

1. Right-click on iPhoto and select Show Package Contents.
2. Go to the Contents/Resources/English.lproj folder. (For our non-English speaking readers, just open the appropriate lproj folder - Spanish.lproj, German.lproj, French.lproj, etc. Hmmm... did I just give English instructions to our non-English audience?!? At least I tried...)
3. Make a duplicate of the file InfoPanel.nib by right-clicking on it and selecting Duplicate.
4. Double-click the original InfoPanel.nib file. This will open Interface Builder.
5. Go to the Tools menu and select Show Inspector.
6. Go to the Exposure tab.
7. Click on the Show button next to the GPS fields.
8. Go to the Edit menu and select Duplicate
9. Ctrl-click on the new Show button and drag it to blue translucent box named File's Owner
10. In the Inspector an action called ShowGPS: should be highlighted. Click on the Connect button.
11. Save the modified InfoPanel.nib file and fire up iPhoto.

Otherwise, if you don't have XCode or you just can't be bothered with the 11-step DIY above, you can just download the modified InfoPanel.nib file here.

Just be sure to backup the original one since the modification page "breaks" the Keyword checkboxes.

You may need to select Show Info twice the first time around, but if you have GPS information in your pictures, you'll see that clicking on the Show button fires up your default browser with Google Maps showing the location.

WARNING:
Once you're finished playing around with this hack, we highly encourage restoring the original InfoPanel.nib file. Even though the latest version by IntrepidAntipodean doesn't seem to break anything, we bear no responsibility if you inadvertently loose any data. You've been warned.