Don't do it!!! Hard drives come from the factory with somthing called "low-level fomatting" on them (which is not the same as normal formatting for Fat32, or NTFS, or any other file system). If you bulk erase it, your OS will not be able to format it again, and you will have a nice shiney door-stop. :nono:
There used to be some DOS utilities that could perform low level formatting, but they were a serious PITA to use, and they often had to be tricked into working on large hard drives. I do not recommend this process at all unless you want to waste an entire weekend pulling your hair out.
If you want to quasi-erase a hard drive, then just reformat it with a different file system. This will not erase to anything approaching millitary standards, but it is not exactly easy to recover data from this either. Wrting 0s is the best way to truly erase.
If your goal is to erase to throw away, then I would write random 1s and 0s to it.