Everyone knows the way to count is by sight, right? Not necessarily.

A subtle way to get the job done is to find dealers who mention the values of the cards as they're played. This occurs almost exclusively in shoe games (and mainly on the East Coast) where all cards are typically dealt face-up on the table. Many dealers will assist patrons by announcing their totals following hits.

For example, if you see that a player has a total of 10 before hitting, and then hear the dealer say that his new total is 16 after the hit, you know that the card was a 6, and has a card-counting value of +1. You can actually turn away from the table, apparently not interested in the outcome of the other hands, while maintaining the count all along.

The best way to make use of this technique is to first locate such a dealer. The best kind is one who announces each player's total after the first two cards, then again after every hit. First count the value of the cards initially dealt to the players. You may now be able to direct your attention away from the table (look for a cocktail waitress, chat while facing the pit boss, etc.), mentally keeping track of the count based on the dealer's announcements. It takes a while to get the hang of it, but counting by sound is a lot of fun, and good cover when done correctly.