WDF is now using the XenForo software, which is different in many ways from the vBulletin software most forum posters are used to. Many vBulletin forums include a feature known as Reputation. XenForo has a similar feature, except that it follows the Facebook logic and is known as "Like".
So how do you "Like" a post? For the purposes of this mini-tutorial, I'm going to use one of AlphaMare's posts, which I've screen captured below:
http://www.adamwebdesign.ca/WDF/post-i-like.jpg
On the bottom right corner of each post, below the user's signature (if applicable), is the "Like" link, along with a permalink to the post itself and a reply with quote button. I've highlighted the "Like" link myself just to make it easier to spot.
In order to Like a post, simply click this link. You don't need to do anything else. You should see a result similar to the one I've posted below:
http://www.adamwebdesign.ca/WDF/liked-post.jpg
The area I've highlighted in red shows that you now "Like" the post.
Some of you may notice that "Likes Received" did not increase on the left hand side of the post, which contains a summary of the poster's activities and location. This is normal, and if you either refresh the thread you're on or leave it and come back to it, the Likes Received will increase.
Hopefully this clears some things up for people.