You will find that there are quite a few rooms in Vegas that allow dealers to play in their own poker rooms, although not as many of them allow the dealers to play while on shift although I know that both the Riviera and Treasure Island do.  Usually dealers are only allowed to join a game when a room is slow and they are overstaffed.  The dealers are allowed to play to help keep games going but they are playing with their own money and they are trying to win.  You might ask the floor person when you play if dealers are allowed to play in the room and if they have any restrictions-for instance in some places dealers are not allowed to check/raise if they are playing while on the clock.  Outside of getting on a table full of drunken players who don't know how to play, a table full of dealers might be your best opportunity to win money in Vegas!!!