This appeals to me; I am not sufficiently knowledgeable to deserve a few lines here, but I often simply want to show my agreement with another member's viewpoint, or let them know just how much I appreciate their contribution, or how excellent it is. One might even simply want to know more. Furthermore, sometimes one wants to do this to a thread that is now several comments away, and most people have cut & pasted that upon which they wish to remark. (I haven't yet worked out how to do that, which is occasionally a nuisance.) If one could merely button-press a response to a contribution, I think it could be very useful.