We do have a keyword nodelet for attaching keywords to nodes but I don't think it is used very much. I don't use it myself at any rate.

I kind of see how this might be interesting but I don't see it as fitting in here. One of the things that seems to make the voting system work so well (if you are like me and believe it does) is its simplicity. I don't think I'd be motivated to categorize nodes but a simple upvote, downvote, or don't bother decision takes very little thought.

Relatively speaking, most posts here seem to be on-topic. There isn't much of a problem at all with OT posts. Even the ones that are off-topic are as likely as not to be marked as such in the subject and if they aren't they are usually quickly considered for that edit. As you noted yourself, if they are way off-topic or offensive they get considered for deletion.

Finally, the Super Search does help a great deal in finding nodes if you are interested in a particular subject or have a particular question.

-sauoq
"My two cents aren't worth a dime.";