These virtual tours/field trips have been useful in a social studies class that I teach called Passport to the World. Let me know if you find them useful or if you recommend others. I especially like the Anne Frank House resource.
Nova, the highest rated science series on television and most watch documentary series on public television, has created virtual field trip for public viewing. This is the most acclaimed TV series and has won almost every major television award - most many times over. This particular virtual field trip relates to ancient Egypt:
Tour of Italy is a website created by expatriates with the aim to provide rich imagery of Italy in its historical and cultural contexts:
Independence Hall Association (IHA) - "The IHA owns the website ushistory.org, which supports our mission to educate the public about the Revolutionary and Colonial eras of American history, as well as Philadelphia generally."
3-D Virtual Tour of the Anne Frank House
White House Virtual and Interactive Tour:
Virtual Tour of Submarines: