You need to just give more information about this.
I have found that meet ups get more notice when you state exactly what you want to do and where it's going to be held, and then people can talk about when...
When you just say 'hey, I want to hang out with people, when and where should we do it?' a lot of people just kinda ignore/look over it.
Not trying to be rude, this does sound like fun ^^ just trying to help ya out!
So, you should just pick a mall right now and see what people show interest. Btw, don't do Lloyd mall, since they really don't like large groups of cosplayers, especially the cosplayers who have the more extreme costumes...
Pioneer Mall is a good mall and doesn't totally hate us, plus there are good places for pictures if wanted.
Beaverton Mall, aka Ceder Hills Mall is good, but small and there really isn't much to do there...Personally, I'd probably just leave after a while and go raid Goodwill or something... >>
Clackamas Mall is really good, as long as you notify them a head of time and it's accesable by the MAX, and I know there aren't that many people who get the chance to go there (like me ^^;)
Just throwing those out there. So, as I said, you should pick a mall and state what you're wanting to do, and then start talking about dates/times.