bcworkz, you are correct, I am already doing this. I run a WP_Query and then the very next line is an if statement that leads into an insert_post statement so there is very little time between query and post insertion.
I haven’t seen any sort of write locking in WordPress, though I have been looking. I was hoping to avoid writing my own database access methods, but it looks like I just might have to do that. I also tried to use PHP semaphores, but then I found out that the shared hosting I am on doesn’t have the PHP semaphores package installed.
If anyone has any further ideas, I’ll gladly accept them. Thanks!