To stop LeBron we have to make sure our team defense is top notch, making sure we give his defender tons of help especially when he tries to drive the lane. If we can keep him out of the lane, but clogging it and helping a lot when he makes a move, we can try to keep him as a jump shooter. He is not as dangerous a shooter as when he is getting his way to the basket an getting foul calls. That's the best chance we have, and we have done it before.
While all of the above is true, I believe everyone (including the coaching staff) is looking at this situation the wrong way. As we all know, when the Bad Boys were beating Jordan in the postseason, the only thing they concentrated on (aside from the brutality and mind games) was how to stop Michael through their team defense; what they failed to do however, was make MJ play defense for the entire game and thus wear him out. I think that for the Celtics to win, our team defense must be excellent on everyone (do not over help or let the other players get off). Instead of letting him rest on the offensive end, Boston needs to attack James relentlessly for 48 minutes and hopefully get him into foul trouble. Now, I know that everyone will say that you can't get LeBron in foul trouble because of who he is; I understand this argument, but I do think it is possible to put James on the bench with 2 personals - plus, even if we don't get the correct calls from the officials (which never has, and never will happen), we are at least sapping his strength from having to defend many different players. I say we have Pierce, Leon, Rondo, Marbury, Ray, and everyone else attack him relentlessly. Take him in the post (Leon, Paul), take him off the dribble (Paul, Marbury, Rondo, Ray), make him chase Ray Allen all over the court, try Giddens (athleticism and great length) and/or Walker on him (this is where having Bonzi Wells would really help - get to it Danny), and I think we have an excellent chance to win (even without KG). Remember, you don't have to worry about defending LeBron if he's on the bench. And oh yeah, run the hell out of Big Z, Joe Smith, Floppy, and Wally. Attack, attack, attack.