Hi,
By IP obfusation I assume you mean the technique of using the decimal value of an IP address instead of the more common dotted quad notation. For those who don't know IP addresses are in fact 32 bit numbers and dotted quad notation splits the number up into 4 x 8 bit numbers to make it easier for humans to read. For example the IP address 1.2.3.4 equals the  decimal number 16909060...

1 * (2 ^ 24) = 16777216
2 * (2 ^ 16) = 131072
3 * (2 ^  8) = 768
4 * (2 ^  0) = 4

Total = 16909060

As far as security goes I can't see a good reason to use IP obfuscation. I've only really seen it used for obfuscating URLs to fool the punter into thinking they are visiting a host other than the one they are really hitting. If you want to do this then by all means use it, but if you want to conceal URLs from view it's pretty poor. It will also not work if you are using name-based virtual hosts on your web server.

Regards,
Jim