Well, I might not be able to think of everything at once. It would be great to have a lot of games loaded and be able to flip from one to another instantly. It would be nice to have some sort of screen showing the names of the opponents and if you clicked on Kasparov-Topolov you would see the current state of the game and could easily display the game score, and you could do that with a large number of the participants in the tournament.

Players might be watching the Chess Olympiads, with literally hundreds of players.

Something that is not done now that would be innovative would be to be able to display information from several chess sites at once, so you could see lots of commentary from all over. That might require too big a screen, however.

Webcams are common these days, and if they are available you would want to have that video somewhere.

What people like to do with chess databases is see the history of the opening, so you know that this variant of the Ruy was played a bunch of times in 1997 but not much since then, and that move 13 is a theoretical novelty. People like to see computer analysis as well.

If you are playing on FICS, you of course want to see the window showing graphically who is challenging under what time.

So, there's a lot you could wish for in a viewer.

I hear that ICC has "cheat detectors," increasingly important as players learn to integrate computers into their online play. My impression is that ICC has one technique that detects impossibly rapid moves.

I'm not exactly sure how that works, because I am a firm believer in the 'premove' feature, which means you can indicate beforehand the move you will make as soon as your opponent moves, and your interface makes the move instantly after the opponent moves. To me, this is essential in fast games.

These are some random ideas, of varying quality and in no order.