leading your boss

What is the difference in leading up vs kissing up? If I am doing something for my boss; giving him some information or doing him a favor that I know is going to make him look good and by doing so he will somehow be inclined to treat me especially favorably, that is kissing up.
On the other hand if I can give my boss a resource, or connect him in some way to something that will help him achieve his professional goals - which should be aligned exactly with the goals of the organization - then I have exhibited reliability, servanthood, resourcefulness, which in turn builds trust- which of course translates into influence.
We could simplify it and say that the difference between leading and kissing up is motive- but I think it's more specific and observable than that. I think you can actually see the difference between kissing up and leading up. For instance, we have all seen the "kiss up". He's the guy who laughs at the bosses' jokes that are not really funny. He likes to sit next to the boss. He happens to mention to others in the organization how close he and the boss have become.
The one who is leading up is almost always less obvious. He influences behind the scenes- not in secret- but not needing others to know how he's helping the boss. He only laughs at the jokes if they are funny, and he often tells the boss things he doesn't want to hear, but things he needs to hear.
The amazing thing about leading up is that it truly is servant leadership in its purest form. We have to invert our minds to think of serving those who are beneath us on the org chart- but when leading up it seems obvious to us that we would serve those above us. What we often miss is the considerable influence we can have when we are actually underneath a strong leader.
A strong leader actually knows his own weaknesses and seeks out people who will support him in those specific areas. When he finds one, he will make sure that person stays close and consult him when looking for an honest opinion on a situation. An honest and trustworthy 'second fiddle' is arguably the most valuable resource any leader has. 'Second-fiddle' is often the most influential instrument in an organization.
So if you are in the second (or third chair) and you know you have some influence, how can you be intentional about using your influence to help your leader and the organization you both serve?