That's pretty much the only way I end up riding with someone else! I like that actually, you don't feel like you have to stick together if the skill levels are really different, or you want to take off and explore a different trail...

Anyhow, I think you're dry erase board idea is great, and not overkill at all. I could be a lot more thorough like that, especially during the week when there's not the usual army of hikers out there who might stumble across me.