Converting an IP Address to an Integer and vice-versa

Overview
Notes, notes, notes...

IPv4 Address to Integer
To convert an IP address to integer, break it into four octets. E.g.:

First Octet: 	58 Second Octet: 	71 Third Octet: 	34 Fourth Octet: 	137 To calculate the decimal address from a dotted string, perform the following calculation.

(first octet * 256^3) + (second octet * 256^2) + (third octet * 256) + (fourth octet) = 	(first octet * 16777216) + (second octet * 65536) + (third octet * 256) + (fourth octet) = 	(58 * 16777216) + (71 * 65536) + (34 * 256) + (137) = 	977740425

or

Convert each octet to binary, append them, and convert the resulting string into decimal.

Use ip2long in PHP.

IPv6 Address to Integer
Hmmm... maybe I'll just strip off the colons and convert from hex to decimal?