Here is a good way to remember the first 7 digits of pi:
How I Wish I could calculate Pi
Write this down on a piece of paper. “How” has three letters, then place a dot like this:
Now count the letters of the rest of the words in “How I wish I could calculate pi” and write them down after the dot:
Those are the first 7 digits of pi, which goes on and on forever…
I got this tip from reading this book in the bookstore over lunch:
Need more digits?
Here is website that has a mnemonic for the first 402 digits: