Remember the milk (RTM) implementation would really make rainlendar perfect!
My point in using rainlendar pro is to be able to use it from my two computers.
With google calendar implementation, this is now possible on the calendar side, but it would be awesome if RTM support could be implemented to fulfill an online approach!
As pointed out, RTM seemes to provide a nice API for this.
An example is a module in netvibes ( eco.netvibes.com/widgets/19506/remember-the-milk
) that integrates with the RTM service very nice.
I really think this is a good idea