Zero an OS X hard drive without reboot CD?

I have a MacBook, and need to zero the hard drive, because I am giving the computer to someone else, who will have repairs done on it. For privacy purposes, I want to erase everything. However, the CD drive is one of the things that needs to be repaired, and even if I had the reboot CD (the location of which I have no idea), it would just eject it as it does with every CD. So is there any way to erase the hard drive without rebooting and using Disk Utility?

There is if you have an external drive.

If not, just remove the hard drive prior to sending it in.

You can not zero the drive you are booted from with any utility.

i wiped an apple drive with paragon drive manager but i am not sure if the drive could be reused in a aplle again i reformated the drive to ntfs for a pc laptop and just put a new one in the apple hope this helps

If you have another Mac and a firewire cable you can start up the MacBook in Firewire target disk mode (hold T at startup) and use the other Mac to erase the drive.

Or..

You could download a Linux Live CD, restore it to a USB drive, and boot from that, then run something like GParted to zero out the drive. Just make sure to format it as FAT or NTFS and not EXT, or else OS X might not recognize it in the future.

There is actually a GParted Live CD which can be booted from USB. It can be found here. You might need access to a Windows PC though.