I have tried a few times in the past without luck to get this working properly. I basically want to sync all my calendars where I can enter an event on any of my devices and have them show up on all calendars. I want this to work for: MobileMe iCal (iMac and MacBook Air) iPhone Yahoo I use MobileMe and it works fine for the first three, but when I add Yahoo into the mix events get duplicated (I sometimes had 4 of the same event on my mac) and a lot of events didn't sync (I think I failed to see events added on Yahoo on MobileMe web calendar. Has anybody gotten this to work successfully? If I could sync Yahoo successfully with any of the other three devices, I feel like MobileMe can take over and get it to work. Thanks.