It would be awesome to have a button on posts that are helpful to thank the author. Ideally, that author could choose to have the # of thanks displayed along with the # of posts. For a solid example, see
AndroidForums.com
It would be nice to thank the kind folks who take the time to share their knowledge. I have grown so much because of this site and met great people. Would be nice to be able to spread some karma this way (if not, perhaps another form of recognition?).
Hopefully this is not a re-post. I did search first, but didn't see anything relevant.
I remember when I came out of lurking I got scolded for my eagerness to 200 posts (for access to the CC) for just thanking people. I ended up getting getting dinged 100 posts for just a few posts of gratitude (oops), heh 
If I'd had this feature, that wouldn't have happened.