This was something over at KawaiiKon that I thought was a good idea. Outside of all the rooms were these long vertical banners (about the size of a long towel) that had artwork on it and listed what the room was. For example, the Main Event room, the game room, the dealer's room, etc. I thought this was a really good idea and it was easy to find all of the rooms.
Also all the banners, along with the different room names, included different artwork so you could also recognize the artwork with the room from a distance. Or if you want to keep the same artwork, have the coloring for the room titles be different. (I.e. Main event room, the game room, the dealer's room)
To be honest I don't know if you guys did this for 2007 or are already planning to do this but I thought I should throw it out there at least.