We all know that when a cat head-butts you, it's showing affection.  And we know that when your cat brings you a dead mouse, it's showing affection (ok, I thought it was showing off or trying to feed me, but what do I know). 

I was just reading this article:

http://www.catchannel.com/news/signs-of-feline-affection.aspx

The blinking thing was interesting.  I was trying to find a link I saw on Slate today, that said that cats just stare at people they don't trust, and that blinking is a sign of trust.  Then I found another article that says if your cat stares fixedly at you, that's a sign of trust.  Apparently there isn't a consensus on that.

Grooming?  Absolutely.  My cat trusts me to pick burrs out of her fur, knowing that I won't hurt her.  She'll just lie there and purr.  But she never does the same for me; what's up with that?

So, who knows?  The one thing I do know is that this article's advice to return the favor isn't going to happen when it comes to dead mice.  I am not going to find a mouse, kill it, and drop it at my cat's feet.   And that cats ARE very affectionate creatures, despite some people thinking they're aloof.  My two cats follow me around, prefer to be in the same room as I am if they aren't outside, and once I go to bed, they burrow close and snuggle the entire night.