Plagiarism.org
This site offers an on-line tool that help instructors detect
plagiarism. This particular tool only checks against on-line material
and papers put into the database by other instructors. This technology
can detect plagiarized papers that contain substituted words or
sentences. A paper's contents are uploaded to the site for remote
processing. As with all such systems, it should be used with care as
the consequences of a wrong charge are high. For instance, one system
called a paper plagiarized when it matched the paper the student put
on-line.
http://www.plagiarism.org/
