I've seen other sites allow the topic starter to mark a topic as resolved, but most do not, and when they do it prevents others that may have the same problem from adding to the topic.
I'm a big fan of help desk software where you would resolve a ticket and create a knowledge base for future reference. As a system administrator of a forum, you probably want a viewer to read about resolving an issue versus rather than pasting the same issue twice. Of course, not all issues start in the same context of others. However, if we cannot add a tag to show a topic closed or resolved, maybe we can have a section on the forum that has resolve issues where a topic creator can message an admin to "move" the topic from the active forum section to the resolved forum section.
What are the storage requirements for an active forum such as this one? What is the projected growth?
I love IP Board - find it much more user friendly than PHPBB, Vbullitin or other forum types. Proboards.com is second.