I volunteered last night at HackerNest Montreal and I got a free t-shirt! I also met some great people and had a nice time.
These meet ups (sign up at meetup.com) are to connect the local tech community in a friendly manner. There is no selling, recruiting or hard sales of any kind. It really is just an event to meet new people in the tech community.
Also, they offer free beer so there is that.
If you are in the tech community or just interested in tech, show up and grab a beer and talk to some nice people. The next meet up is July 27th, see you there!