When command lines go bad
 

One thing that can be a double edged sword in linux is the complete ease of doing administrative stuff via the command line. For instance, you can simply type 'chmod 444 /' as root and mess up the entire system, which happens to be what I just did. Now how exactly do I recover from this?

Can't you just chmod it back to 775 or something?

Yep, and that worked.

chmod 775 is all good and well but, your system is now "VERY" insecure........there are files such as
/etc/shadow and /root that are now readable by users......LOL.........just hope you don't get hacked because crackers can now use your box to send out spam and worms!!