Gulliver's travels contains one episode where Liliput and Blufescu are at war with each other as they hold different views as to which end of an egg must be broken first - Little or Big.
Differences between Shia and Sunni :
The Shia (or Shiatul Ali) are the 'Party of Ali' or those who believed Ali Ibn Abi Talib, the Prophet's cousin and son-in-law, as the rightful successor of the Prophet. The Sunnis did not regard him as the rightful successor.
1. Shia Muslims pray three times a day and combine Maghrib and Isha salat whereas Sunni Muslims pray five times a day.
2. Sunni Muslims fold their arms whereas Shia Muslims do not fold their arms during namaz.
3. Shia Muslims add “Khayr al amaal” whereas Sunni Muslims add “Nawm.”
4. Sunni Muslims touch their heads to the ground whereas Shia Muslims use a wooden block or tablet of clay to rest their heads during prostration.
5. Shia Muslim scholars prohibit the use of word Amen during the namaz whereas Sunni Muslims consider it as a must.
6.Shia sit comfortably on the folded feet whereas Sunni sit on twisted foot and so on.
For these differences, we blow up each other ! !
Heard somewhere: If i am asked to summarise last 2000 years in 2 words, my reply would be : Religion, Science.
While science took us to the moon, religion gave us crusades and extremism - not only in islam but in christianity, hinduism and many religions too.
DISCLAIMER: I was going through this on purely academic interest and reserve no judgement on the following. Hope no one issues a fatwa in my name.