Phillysec gives the following descriptive information:
What is Phillysec?
Phillysec is an informal meetup of information security professionals, researchers, hackers, and academics in Philadelphia.
How do I join?
You don't join, you show up. You have a beer. You introduce yourself if you want and you talk to smart people interested in the same things you are.
Are there presentations?
Maybe. If someone wants to present or give a quick talk and can get the crowd to listen to them, great. This is all very informal.
I'm a security vendor, can I sponsor PhillySec?
Umm, no, but you can buy us drinks! PhillySec is informal and not really a place for vendor pitches however if you're interested in picking up the bar tab I don't think people would mind listening to your 5 minute pitch. Just be prepared for hard questions regarding your service and or product. (If interested in this please DM @PhillySec on twitter for more info.)