Hey Cody if you like and I got this idea from a MMA gym called Counterstrike MMA Academy that also has a website of their own and still uses Meetup.com to get new members. Basically you can copy and paste all of the latest events from ChicagoParkour.net on Meetup.com as a meet up because when people belong to a group on Meetup.com and the organizer sets up a meet up all of the members get an e-mail to let the organizer know if they are going to be showing up to the event or not so that the organizer can plan ahead of time.
Hey its going to be active for a few months why not use it and you can get more traceurs to show up to the events that ChicagoParkour.net lists. I'll provide a link of what I'm talking by using Counterstrike MMA Academy as an example of how you can use ChicagoParkour.net's events to help you get some more people to show up to their events by using Meetup.com as another way of advertising their events. Also I'm a member of the old group but now that I've found some traceurs out here in Northwest Indiana I don't have to go all the way to Chicago or its suburbs to train in Parkour but I wish the best of luck to you as the new organizer of the group.
Counterstrike MMA Academy
http://www.meetup.com/Counterstrike-MMA-Academy/ http://www.counterstrikemma.com/