What I was thinking was something like the thanks button we have in the downloads?
And unlike MTS, I would NOT allow dislike. If you can't find something nice to say say nothing is my motto.
EDIT (kettle was boiling) - I DO worry that if there is a like button then people will not post. I have the thanks thing over on the downloads, but that really is for the convenience of guest users rather than anything else.
It is open to discussion I think.