Here are some ideas I've either used or heard of:
* Agree to mutually register your whereabouts at "Playa Info" at Center Camp. (Make sure there is an exchange of both personal names & camp names ahead of time). If possible, list yourself as "7:50 and C, West [side of street]" to increments of 5, rather than increments of 30 alone. "8 & C" can still technically mean 100 yards North, South, East or West of that actual intersection, and it can be confusing.
* Exchange camp descriptions, tent colors, vehicle colors, flags or no flags, domes, carport presences etc, ahead of time. Even if they get to the right place, they might have no idea who they're looking at if you're in the bathroom.
* Have a white board and tethered marker strapped to a table in your shade so people can leave you messages.
* If you decide to attempt meeting at a location, make it an exact intersection, or something else small, fixed, and easy to find, memorable, like: "outside the ice station on the 3 o'clock plaza every day at 3pm, 3 days in a row until contact is made". Locations that are halfway between you are nice. Wait 10-15 minutes, if no show, try again the next day. (If you try to meet at "Center Camp" or "The Man" it might be difficult unless you're more specific, like "North side".)
* Bring a timepiece to help synch up. You don't have to wear it.
