I made this a while ago, it's still being refined and will be released as a service at some point, but here's a preliminary copy for you to play with. Just enter a comment and press the button, and it will tell you if your comment was stupid or clever.

To clarify, "stupid" and "clever" are only judged on style, not content, so something well-written but erroneous like "The sky is indubitably orange with green stripes" will be judged as clever.

For added fun, try pasting YouTube comments.