yeah, that would suck, better would be a irc bot,
when you get online, your client automatically sends a message to the bot, telling him that he is online.
This put's the player in the refresh list, a list, frequently checked by the irc bot.
This way, only one person/bot/client has to ping the other players, all players just get the online status from the bot.
But, well, I think there will be a webscript, that rtb2 is using to get the status of the players, well, the players send the status.
Messages would also be possible over web, already did all that stuff.