Chris Farrell describes Hollywood Lives (a game I've watched, but not played). I wouldn't characterize it as a Live Action Role Playing game (LARP). To some extent, it's semantics, since LARPing includes a number of subgenres. The one I played is often called "Interactive Literature."
In an Interactive Fiction LARP, people do have a characters sheet, although it's usually much less complicated than a sit down game. The rules are simple (rock paper scissors, roll a single die, pick a card, simon-like memory games). Part of the appeal of Interactive Fiction larps is that they can let you simulate things that you aren't good at (social aspects are always there). Hollywood Lives (as far as I can tell) doesn't have
- Hidden character motivations (or information)
- Rules for resolving unexpected situations (Can an 'actress' blackmail another in game? What about accounting fraud?) [As far as I know in Hollywood, you make deals and trailers, and that's all the rules handle].
- A backstory
I'm not sure which of these are necessary to be a LARP, but there are enough missing that I'm comfortable in calling Hollywood Lives something else. In my mind, it's like Sid Sackson's Haggle with an interactive scoring mechanism. A party game. Not that there's anything wrong with that.
I haven't played or written a LARP in years. Sometimes I miss it (even the writing, but I usually recover quickly).