Remote MySQL servers?

[userdan]

I understand that if you run a lot of database-driven sites, it is usually a good idea to look into using a remote MySQL server to handle the databases. Supposedly MySQL is resource intensive, and having a lot of databases (and their accompanying queries) on your main server can bog the server down.

My question here is, can you setup your server so that it uses remote MySQL? How about offloading an existing MySQL setup onto another server? Since all the sites currently use localhost as the database server, will offloading the MySQL break those sites or can we still keep on using localhost? This is, of course, for a cPanel/WHM server.