I was happily churning along developing something on a Sun workstation,

and was getting a number of annoying permission denieds from trying to

write into a directory heirarchy that I didn't own.  Getting tired of

that, I decided to set the permissions on that subtree to 777 while I

was working, so I wouldn't have to worry about it.  Someone had recently

told me that rather than using plain "su", it was good to use "su -",

but the implications had not yet sunk in.  (You can probably see where

this is going already, but I'll go to the bitter end.)  Anyway, I cd'd

to where I wanted to be, the top of my subtree, and did su -.  Then I

did chmod -R 777.  I then started to wonder why it was taking so damn

long when there were only about 45 files in 20 directories under where I

(thought) I was.  Well, needless to say, su - simulates a real login,

and had put me into root's home directory, /, so I was proceeding to set

file permissions for the whole system to wide open. I aborted it before

it finished, realizing that something was wrong, but this took quite a

while to straighten out.