srm is a secure replacement for rm(1). Unlike the standard rm, it overwrites the data in the target files before unlinking them. This prevents command-line recovery of the data by examining the raw block device. It may also help frustrate physical examination of the disk, although it's unlikely that it can completely prevent that type of recovery. It is, essentially, a paper shredder for sensitive files.
srm is ideal for personal computers or workstations with Internet connections. It can help prevent malicious users from breaking in and undeleting personal files, such as old emails. Because it uses the exact same options as rm(1), srm is simple to use. Just subsitute it for rm whenever you want to destroy files, rather than just unlinking them. For more information on using srm, read the manual page srm(1).
The latest version of srm can always be found on the SourceForge project page which has the source code and binaries for Windows. In addition to the files on SourceForge, other people have added prepackaged versions to the FreeBSD ports collection and Debian.
New releases can be tracked via the SourceForge account. They're also announced on free(code) whenever a new stable version is released.
srm is hosted on SourceForge which provides a convient location for downloads and Subversion.