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.