I broke Leopard with permissions.. help!

I was playing around in System Pref with Leopard's new Sharing features.

I turned on File Sharing and added my whole HDD as a share. It automatically added the users: System Owners (or something similar) Administrators and Everyone.

I removed System Owners thinking i'd only need Admins to be on there and it locked me out of the hard drive completely. Putting a little red no entry symbol next to my HDD.

None of my applications would launch and I rebooted and it just flickers between the mouse and the loading symbol for ever instead of showing the login winow.

Is there a fix? How can I add myself to read/write the HDD again?

steve101.

 

How can I do this without logging in?

The login window just appeared when I turned my macbook on. Entered my password but after that it's just showing the mouse and wallpaper.