Something new over the Google Maps API have been announced this week, KML and GeoRSS are now supported by the API. Maybe you have already met with KML via Google earth, and with this new integration you can view data from external sources inside Google Maps and Earth.
GeoRSS is a data format for geographic content, or simply the way to include location in RSS feeds. Getting this into Google maps can help making amazing mashups. I thought someone can make a travelling blog and add location for each place or entry, adding GeoRSS you could simply add a map view of the blog and see entries about different places ! Easiest way will be to show your Flickr Album since it supports already GeoRSS. I think the possibilities will be amazing especially that now there is a very easy way to integrate these data KML and GeoRSS :
Overlay documentation available
to create killer mashups.
