I've just spent a very enjoyable 2 hours working out how to do the following.
What I needed to do was redirect all the traffic from my old website to my new website.
I am running ubuntu 7.04, apache 2.
Here is what you need to do:-
1. vi /etc/apache2/sites-enabled/000-default
2. Change the word "none" to "all in the following line:
Options Indexes FollowSymLinks MultiViews
3. Add the following code at the bottom of the file:
RewriteRule /.* http://www.siteyouwanttoredirectto.com/