If you watch Google's blogs you'll know that a major new addition as been made to the Google Maps API capablility.

http://googlegeodevelopers.blogspot.com/2008/10/2-lines-of-code-make-world-more.html

I've introduced both of these features on the UK Archaeology Map:

http://www.online-archaeology.co.uk/GoogleMap/

• Click on Layers
• Click either the Panoramio or Wikipedia checkboxes

This is by far the best thing to hit the API for a long time.