Preface: here is the official site for the Blowfish algorithm:
The Blowfish algorithm uses an s-box, which consists of hex digits of pi (found here: http://www.schneier.com/code/constants.txt). I'm guessing that this s-box serves a very similar purpose to the s-box in AES (right?)
However, at the bottom of that file, there is a smaller box called p_array or parray or something. I have no idea what it does! Also, is there some sort of significance to why the hex digits for pi are used, and not some random values?