Oh, and if you want something you can run in Windows, let's say the blanked drive is drive letter F:. Remove all data from F: and then use this command:
cipher /w:F:\
This overwrites all the free space on F: with three layers of encrypted junk, then deletes it all. Not positive, but I believe this would only work if the partition is using the NTFS file system. Probably not as good as DBAN, but I've tried picking up anything off of a drive using PC Inspector file-recovery software after doing a cipher run, and it wasn't coming up with anything but gibberish files.
edit: cipher doesn't take as long as DBAN, about 1 minute per GB on my 15000rpm SCSI drive. It is also safe to run on your C:\ drive, since it only does its thing on whatever space is blank.