My two cents, from working at both a huge Chicago agency and now at a small Raleigh agency: you definitely want to be in the room together, with a personal, human contact element, but most everything these days IS done via computer/projector/Powerpoint, at least as a reference. Also depends on the type of client (high tech vs. low tech, big $ vs. modest budget). Don't want the client to think you're blowing all their budget just on the presentation. You could pitch a new campaign to an existing client for a new product, to reposition and existing product, or even an "image" campaign that's just about the personality of the company and what it makes/sells in general. The creatives (at most, the writer, art director and creative director--at least, the creative director) would present the actual work, while the account exec would handle the setup, recommendations, wrap-up, discussions, etc. Doubtful there'd be any research or media people involved at this level--only when the campaign is closer to being produced and the media being placed. As for the client, you'd usually see 1-3 people from their end, unless this is a "preliminary" meeting that has to clear a hurdle or two before going to the "higher ups" within the client's company. As a courtesy, most client pitches are on their turf, though occasionally we present to clients in our own office, if it's better for their schedule or if our technology is more conducive. Hope this helps!