I've been working on this project for a while with a friend, but it's just about ready for a first release, so I thought I'd post it here and get some response/critique. Mods: feel free to move this!
You need to securely delete some files, but you know (if you don't, you jolly well should!) that the data is still on the disk until it is overwritten. You don't really want to overwrite the entire disk, however.
Overwrite files with random data again and again, so no data is left. This is what programs like shred and srm do. However, you're not really a CLI person. So we came up with shredder, which scrubs files with random data, then removes them from the filesystem table if wished, all through a nice GUI frontend.
Sound good? Well, there is a zipped 64-bit .deb installer attached (sorry to those on 32-bit, I haven't got a 32-bit box to build on), as well as a source tarball (typical installation: make, then sudo make install)
Many filesystems can and do keep fragments, copies, and snapshots of files, so we can't guarantee that your file will be gone. If you really want something gone forever, I suggest something along the lines of Darik's Boot And Nuke, to completely wipe the disk.
If you want to help with this project, drop me a line, and I'll give you instructions and/or encouragement. You'll also get a line in the about box.