www.spammimic.com is a
website offering
strong encryption (well, not really). Type in your short message, and it encodes it into something
100% indistinguishable from
spam (
or your money back).
Type in the encoded fake "spam", hit decode, and it decodes it to your message.
Naturally, emailing (or receiving) spam arouses no suspicions whatsoever on today's Internet...
rara rasputin rightly writes that it's more
steganography than
encryption.