1. Have an ultra fast world, say speed 50, and let it be open for a short period of time somewhere between 6 hours and a weekend.. Maybe the occasional week ones.
2. Have similar speeds to above but to allow for a more sustained play style allow only a set time when people can log on, probably evening between 7 and 9. This method might not work so well but as I said it would mean people aren't going to lose hundreds of cities whilst they brush their teeth.
Pretty sure that's everything, obviously it would need to be balanced so units are travelling reasonable speeds and guilds aren't too hard to manage whilst trying to keep up with the fast pace etc etc
Either way, this sounds really fun to me
