How to make a site accessible from 2 different domains?

[WrzAddiction]

i am not talking about any redirection

i mean making a site xxx.com which can also be accessed through yyy.com

I need to know this as it can be helpful when your site gets blocked by a ISP

like a new thread created would be instantly visible on both sites

Link eg:
New Thread:

http://www.xxx.com/newthread.php?do=newthread&f=53
http://www.yyy.com/newthread.php?do=newthread&f=53

First one is blocked and second one is not blocked by any ISP

i have seen some sites using this method..so asking how it is done

WrzAddiction Reviewed by WrzAddiction on 2nd Nov 2010. How to make a site accessible from 2 different domains? i am not talking about any redirection i mean making a site xxx.com which can also be accessed through yyy.com I need to know this as it can be helpful when your site gets blocked by a ISP like a new thread created would be instantly visible on both sites Link eg: New Thread: Rating: 5

[Mr Happy]

If you have your main site set up as xxx.com you can then add yyy.com as an addon domain but specify the same root folder as xxx.com.

That's the way I did it but I'd be interested in hearing if their's a better way.

Their are other things to take into account. I was using a custom script and the script knew which domain was looking at it and changed the language pack that was displayed.

The things you'll need to take into consideration are duplicate content and Google. You'll have exactly the same pages under two domains. Now you can specify a meta anchor tag (think that's what it's called) which will tell Google which of them to index.
The other thing you have to think about is if it's a forum you have to specify the domain name in the script which is saved in the database. This could cause problems in some links on the forum depending on your script but I'm not fully sure to be honest.