Here's how I'd do it (bear in mind I'm no PHP whiz). I'd make a function somewhere called "counterShow" and one called "counterIncrement" or something, and just execute the counterIncrement function when the board index is loaded (or when the user logs in, or whatever). Then at the precise location you want the counter to show up, just execute counterShow.
The Show function of course, reads the value stored in a variable like $counterHits, while the Increment function increments the variable. Very, very simple stuff in PHP. Of course, you also have to store that somewhere... probably in your database.
Just a thought for those who understand PHP/MySQL a little: It'd be a good idea to figure out a way to use an existing MySQL query to read and write the data to the table, if at all possible, rather than creating a new one; my understanding is, anytime you run a new query it uses up server resources and can slow down your board, whereas "piggybacking" or accessing the results of an existing query simply uses the information already stored in memory and does use more system resources.

This is something simple I could easily do if I had the time or motivation to do it.