Currently Being ModeratedNov 6, 2011 5:41 PM (in response to simplemo)
icloud is part of iOS5 which runs on the 3GS ( not on the 3G ), so everything in iCloud will work.
To be able to sync between other devices, they must all run also iOS5 and for a Mac 10.7.2 Lion. PCs with XP wont work as Vista is needed.
So if you have Macs that can't run Lion, PCs that don't have Vista/Win7 with Outlook07 / 10 or iOS devices that can't run version5 these will no longer sync with the iOS5 3GS.