How can I distinguish the difference between a male and female iguana?

I'm not sure if my iguana is a boy or a girl. How can I tell?

Males have a series of big holes in a line down the inside of the thigh called femoral pores. These are very small or absent in females. Males also look bulgier in the area just behind the cloaca, where the hemipenes reside. Sometimes if you carefully squeeze on this area, the hemipenes will evert.

I also want to add that males will have pronounced bulges at the base of the skull.Check out: http://www.greenigsociety.org/It has a section on gender differences, as well as a wealth of other information on care of your iguana.