Originally I considered having a full-fledged searchable request log, but the resources that would suck up don't really seem worth it when I could just grep access.log.

Rather, I'm now considering a combination with another idea I was considering: an administration log.

I propose creating an action_log table, that logs any (significant, i.e. POST) changes made anywhere. It would have columns for the type of change (often referring to a specific table), possibly a type of action (create/delete?), a foreign key, and an IP. Thus every post's IP would be logged, every shout's IP would be logged, every upload's IP would be logged, AND the IPs for edits and deletions and so forth would also become part of the table.

Since the columns will all be fixed-width (I presume the type of change will be an ENUM or foreign key, not a string), lookups and searches should be fast. The table will also remain fairly small; no more rows than in several other tables combined, and each row will be quite short. This can be an incredible improvement upon phpbb2's existing IP button.