just make sure you don't read or write too much to your drive in between now and when you run the program.
You're not screwed, check out this link:
http://www.prosofteng.com/products/data_rescue_info.php
The program is amazing, i recovered 34gig of data once with this
just make sure you don't read or write too much to your drive in between now and when you run the program.
you will need an external drive to write the information to.
good luck
Just wait for Leopard to come out. Then use Time Machine to revers you mistake.
Don't wait for time machine, learn to backup now. Computers are educational: sooner or later they will teach you to backup.