Made a mistake: Settings URL

Hi folks,

So, I use MAMP to edit my site.
I don’t know what I was thinking, but I was mucking around with my settings URL which you can see here (http://codex.wordpress.org/Settings_General_Screen) and changed it from the localhost address to my domain name to see what would happen.

Well, now I can’t edit my site using Apachee and the MySQL server on MAMP won’t start.

Any ideas how I might be able to fix this issue so I can access my site through the localhost again? (seeing as I can’t go back in and change it).

Cheers.