For ages I've been having the idea of an 18xx style game about the "new economy" of the 1990s dotcom boom. The main feature would be that the stock market would work exactly the other way around: if you pay dividends, your stock goes down, but if you withhold and invest in growth, your stock goes up, reflecting all those internet startups that never made any profit but were still valued incredibly high.

I never really figured out how the operational aspect of the game should work, though.