A possibility: have a sub-section of discussion or a sub-section of the main page just for meetups and related topics like planning, recaps of the meetup that you just attended, etc.
It took someone pointing out this discussion section to me for me to find it; visibility (particularly if your goal is community-building) seems pretty important. I suppose if you entitle the section "meetup" or something it might be more readily visible, but I know I'm much more likely to go to an Austin LW meetup if it is presented to me than if I need to go find it.
Does anyone else think we need a better way of dealing with meet-ups? I totally understand that meeting face to face is an (at least arguably) important next-step in the rationalist-community-building project, but the fact is the front page, which was originally for all the most content-rich, accessible, and noteworthy articles is now being filled with blurbs that are irrelevant to 95% of the readership.
I can see why these posts would need to be highly visible if the meetups are going to work at all, but I think we should get the ball rolling on figuring out a better way to handle location-specific posts. For example, mandatory-but-private location setting in your profile (at least to the country, possibly to the state/province/etc for larger areas), which would subscribe you (with opt-out available) to any happenings in that area. That's just the first idea, like I said the idea is just to get the discussion going.