Domain name and multiple sites

Hi all.

Simply put, I am wondering about having my site on several different servers, but keep my 1 domain name.

One implementation of this would be I can choose the server where the site is hosted whenever I need to, and switch the site over to that server. But I want to keep my domain name the same for access to users. So I have 3 sites, on 3 IP addresses, all independent, and a domain www.whatever.com, and I can determine at will which IP address the domain applies to without "officially" moving the dns to that IP. What are the possibilities for this?

Another implementation of this concept might be instead that the user comes to my central main page, where he clicks on a region in the world that is closest to him, and is forwarded to that server's mirror of the site. But in his address bar, it would still display as: www.whatever.com. Possible?

I will move all my data to sql server, so there is no concern about data sync.
Just want to be able to have several hosting sites where I can instantaneously decide which one is the domain. Either solution is okay by me.

Ideas?
Thanks
Wengang

Here is an article that may point you in the right direction. Many large web companies do what's called load balancing. They have the same web site on multiple servers and when one gets to busy it switches to another. SO take a look at this article and research load balancing.
http://www.onjava.com/pub/a/onjava/2001/09/26/load.html

thanks. I will take a look now.

yes, the article looks very informative. Just hope I can follow it. That's the sort of solution we're looking for.

Thanks again.