BURNINGTHUMB The information on rixstep is obsolete. Gutmann revised his paper but rixstep "forgot" to revise their site.
The 35 overwrites is just wearing out your hard disk, its not doing a "better" job - that's the gist of Gutmanns revision.
We do make ShredIt X which is a perfect GUI file, folder, disk free space, and optical CDRW shredder. It also includes a safe place feature (sorry command line fans no safe place for you to keep things) so that you don't accidentally shred important files.
(Version 4.2.2)