There is something called piphilology which basically is the use of mnemonic techniques to remember pi.
One of my favourites is this poem:
Pie
I wish I could determine pi
Eureka, cried the great inventor
Christmas pudding, Christmas pie
Is the problem's very center.
So, the letters in each word corresponds to a digit in pi.
i.e. Pie (3), I (1), wish (4), I (1), could (5), determine (9), pi (2) etc. gives 3.141592