tl;dr Maybe we can post here when we have open spaces in our Yosemite campsites that we are willing to share with others to split costs and combine campfire stories.
1. I have a site in Yosemite for this weekend (Nov 15–17, Fri–Sun), which has additional room for 1 car and 4 more people. If you reply to me (PM) in such a way that you demonstrate that you are a real, kind, and quiet (we are gonna be up really early so we can flog ourselves all day), you are welcome to share the site with us! We'll split costs by person. Let me know your plan.
2. I often find myself wanting camping in the Valley, and often times people (like me) will have site reservations which would fit more cars and people. I wonder whether this thread might be an enduring place for people to post when they have space in their site they can offer up. I wager this has already been done before, but I'm sure the internet hordes will provide some strong opinions on whether this is useful.
Skip the dirtbag; meet new people; crush and be crushed.
Jeff B wrote: How likely is getting a site at camp 4 if you drove up on a Friday night?
This was my concern. I find it generally worth it to nab a site if available to have confidence of a place to sleep when arriving in the dark and intending to wake up super early for a larger objective. I know that Camp 4 is still generally full on all of the weekends, even in November (or at least, this is what rangers have told me).
Either way, I think having a place for people to post site space would be useful, certainly once summer comes around again.