I am considering allowing users to post to my site without having them register or provide any identifying information. If each post is sent to a db queue and I then manually screen these posts, what sort of issues might I run into? How might I handle those issues?
Screening every post would be tedious and tiresome. And prone to annoying admin spam. My suggestion would be to automate as much of screening as possible. And besides, providing any identifying information does nothing to prevent spam (a bot will just generate it).
A lot of projects implement recognition system: first the user has to post 1-2 posts that are approved, then by IP and (maybe) a cookie he's identified as a trusted poster, so his posts appear automatically (and later can be marked as spam).
Also some heuristics on the content of the post could be used (like amount of links in the post) to automatically discard potential spam posts.