Pit workers and anyone else around. This is funny as hell and I've seen my friend do it a few times...
When hitting up to a total of 21 (anyone who plays knows in a split-second when their cards reach 21), act like you don't know what you have...
THEN, act like you're using your fingers to SLOWLY add up your total..
Wait to see who snaps first. Usually it's a fellow player who's pissed off that THEY don't have 21. Sometimes it's the dealer who you haven't been toking. And yet other times is the Pit person, who oddly seems to sweat it whenever the table is making any dough.
Good for a laugh!