The state of Pennsylvania has just launched a new portal
Of particular note is the impressive GigaPan imagery throughout the map; massive images of battlefields and other noteworthy areas that can be explored similarly to the Gigapxl Photos in Google Earth.
You can check it out for yourself from the Google Earth page
About Mickey Mellen
Mickey has been using Google Earth since it was released in 2005, and has created a variety of geo-related sites including Google Earth Hacks. He runs a web design firm in Marietta, GA, where he lives with his wife and two kids.