Now that we have the new forums this subject has many new ways to be satisfied.
A) find the posts where people have told you something, provided something, helped in your appreciation of the game and hit the "Thanks" button on the post.
B) click on the scales icon at the top of a post and add to that persons reputation
C) and of course, the good old thank you note is always appreciated also.
You can help keep things rolling with your please and thankyous.
Gandalf Parker