The biggest wall that prevents people from participating in LARP games is the harsh stereotyping that we receive. The general public tends to assume that these games are only played by social outcasts, and therefore trying a LARP will make you a social outcast.

What we do is a game, no different than playing Dungeons and Dragons, paintballing, or even the board game Axis & Allies. You will have to defend this point over and over again throughout the life of your game. You will be confronted by a nasty stereotype or compared unfavorably to another game. Your reaction is going to reflect on LARPing in general, so you need to be prepared. Here are some Do's and Don'ts when it comes to dealing with stereotypes.

Don't Attack Other Media
Someone will compare your game to World of Warcraft or some other video game. The correct response is not to promote your LARP at the expense of the other game. That person is probably trying to relate to your game using something they're familar with. If you attack a game someone identifies with, you might as well be attacking the person directly. Instead, establish links between the your LARP and the other game (all games have links).
DON'T - "That game is boring. This game is much more exciting."
DO - "Just like ___, this game let's you create a character to interact with others - it's just a little more personal."

Don't Get Defensive
Unfortunately, most of the media out there about LARP is not very favorable to our game. People are far more familiar with things like Monster Camp, which focuses on what I like to call the "Dark Side of LARP." While there is entertainment value in those videos, they present an awkward face to viewers who don't know the context. Instead of getting defensive, explain the context behind the videos and compare it to something they can relate to. Remember, there are outliers for every group.