Ok, so I'm a day or two late on this one, but as my 8th grade English teacher used to say: "Better Never than Late." With that in mind, lets look into the frenzy that occurred over the game winning goal by the Sharks over the Red Wings. The most important part of this rule is not the "what it prohibits" but "how to exploit it."
Nightmare on Helm Street.
Yes, there are seven Sharks' skaters on the ice in the photo. Foul! Foul! Right? No.
There is a five foot rule exception According to Rule 74:
Too Many Men on the Ice - Players and goalkeepers may be changed at any time during the play from the players’ bench provided that the player or players leaving the ice shall be within five feet (5') of his players’ bench and out of the play before the change is made. Refer also to Rule 71 – Premature Substitution. At the discretion of the on-ice officials, should a substituting player come onto the ice before his teammate is within the five foot (5’) limit of the players’ bench (and therefore clearly causing his team to have too many players on the ice), then a bench minor penalty may be assessed.
Exploiting the Rule:
The Benches are 24 feet long. Players get 5 feet of buffer. Thats 29 feet a the team can gain, for example on a break away. Take this example from the Preds' playoff win over Chicago. If the Chicago player had been at the top of the screen (i.e. near the bench) instead of at the top, a lot of ground could have been made up on this play, maybe even potentially broken up.
Sure, this rule isn't exploited very often, Its hard to plan, as all of the variables have to be exactly right: the timing, player positioning, skating full speed may be quicker than accelerating. Regardless it is still a trick thats good to have in your back pocket.
I will say that the trick is more valuable in beer league games where, well... lets just say that the game isn't quite NHL speed.