What does it being a notebook have to do with anything?
If the data is important, stop using the computer. Try the Data Rescue software. Of course, you will need to boot the computer and install the Data Rescue software, so the erased data may be overwritten during this process.
Data Rescue may work over a network, so you may be able to install it on a different Macintosh, then connect via ethernet or something to the laptop and run Data Rescue over the network.
Your other choice is to send the drive off to someone like DriveSavers (
http://www.drivesavers.com/ ), and that'll cost you a few hundred dollars -- possibly up to $1000 -- to recover the data, if it's recoverable at all.
Or, you could restore the data from your backup...

You do have a backup, right?