You know like Facebook does?
I mean when you're reading a long thread, or you've joined a thread late...there are times you want to say "I agree with so and so" or "Good post so and so" but they've posted too far back so it wouldn't make sense.
Also, I always feel a bit rude if someone's posted say....
@ worra (yes it does occasionally happen!!) and I can't really acknowledge that post later on.
A 'like' button would surely right all that's wrong in the world would it not? 