Offer free beer.

Have a policy of inviting every chick.

first of all, where do you live and what do you expect from these security groups? if your looking for people with the same interest you have in technology and hacking you can start with going to hackerspaces:

http://hackerspaces.org/wiki/

also the 2600 phreakers group has a chapter in almost every big country??

try hooking up, and go to meetings/conferences/workshops! see and be seen!