After studying Chinese for several years, the following wikipedia entry doesn't suprise me as much as it probably should:
The Lion-Eating Poet in the Stone Den (simplified Chinese: 施氏食狮史; traditional Chinese: 施氏食獅史; pinyin: Shī Shì shí shī shǐ) is a famous example of constrained writing by Yuen Ren Chao which consists of 92 characters, all with the sound shi in different tones when read in Mandarin.« Shī Shì shí shī shǐ »
Shíshì shīshì Shī Shì, shì shī, shì shí shí shī.
Shì shíshí shì shì shì shī.
Shí shí, shì shí shī shì shì.
Shì shí, shì Shī Shì shì shì.
Shì shì shì shí shī, shì shǐ shì, shǐ shì shí shī shìshì.
Shì shí shì shí shī shī, shì shíshì.
Shíshì shī, Shì shǐ shì shì shíshì.
Shíshì shì, Shì shǐ shì shí shì shí shī.
Shí shí, shǐ shí shì shí shī, shí shí shí shī shī.
Shì shì shì shì.
I love tonal languages.