I have to agree with Mark's sentiments - a group meal and beer should be on the agenda, but the focus should be on our common interest. Jillians sounds like a great place, but perhaps not ideal for our needs.

For the afternoon we need somewhere where:
a) We can park as many cars as we need close together.
b) Is cheap or free - Let's try to keep the expense down to encourage a higher turnout.
c) Is a pleasant place to be for a few hours. (Downtown parking lots don't do it for me.)
d) Has some sheltered public space nearby, so that any mods that people may wish to do can be done, and in case the weather is bad.
e) Is somewhere where significant others and families might want to be even if they are not as fanatical about hacking the empeg as we are.
f) Is somewhere where we could get some good photos. (to view on our empegs with the viewer I wished for yesterday )
g) Somewhere where we don't have to get a minimum number of people to make work.

For the evening, I'd think that somewhere where we can get a good meal for lots of people that isn't expensive is a good plan, and then either a large pub or somewhere like Jillians (but now we don't have to worry about the minimum number or the expense of a dedicated function room)..

Just my 2c.