FlipText is a free website that does just one thing – it flips your text upside down. Whatever you write is flipped upside down. Then you can copy it and use for….. not sure what you would use the upside down text for. But it is hell lot of fun.

FlipText supports multiple languages: English, Spanish, French, and German. The website itself is extremely easy to use. Just enter the text to convert in the top textbox, and FlipText will keep converting that to upside down in a separate text box.
Passage above text flipped:

˙xoq ʇxǝʇ ǝʇɐɹɐdǝs ɐ uı uʍop ǝpısdn oʇ ʇɐɥʇ ƃuıʇɹǝʌuoɔ dǝǝʞ llıʍ ʇxǝʇdılɟ puɐ 'xoqʇxǝʇ doʇ ǝɥʇ uı ʇɹǝʌuoɔ oʇ ʇxǝʇ ǝɥʇ ɹǝʇuǝ ʇsnɾ ˙ǝsn oʇ ʎsɐǝ ʎlǝɯǝɹʇxǝ sı ɟlǝsʇı ǝʇısqǝʍ ǝɥʇ ˙uɐɯɹǝƃ puɐ 'ɥɔuǝɹɟ 'ɥsıuɐds 'ɥsılƃuǝ :sǝƃɐnƃuɐl ǝldıʇlnɯ sʇɹoddns ʇxǝʇdılɟ

˙unɟ ɟo ʇol llǝɥ sı ʇı ʇnq ˙ɹoɟ ʇxǝʇ uʍop ǝpısdn ǝɥʇ ǝsn plnoʍ noʎ ʇɐɥʍ ǝɹns ʇou ˙˙…ɹoɟ ǝsn puɐ ʇı ʎdoɔ uɐɔ noʎ uǝɥʇ ˙uʍop ǝpısdn pǝddılɟ sı ǝʇıɹʍ noʎ ɹǝʌǝʇɐɥʍ ˙uʍop ǝpısdn ʇxǝʇ ɹnoʎ sdılɟ ʇı – ƃuıɥʇ ǝuo ʇsnɾ sǝop ʇɐɥʇ ǝʇısqǝʍ ǝǝɹɟ ɐ sı ʇxǝʇdılɟ

Link: FlipText