First up, the service improvements:
As part of an update to the MobileMe web applications, you can now access Find My iPhone directly from the MobileMe toolbar. This support article contains information about this and other service improvements.
Your iDisk Public folder, a place where you can share files with friends, now matches the look of me.com and supports drag and drop for moving files between folders. You can manage your Public folder preferences at me.com including allowing visitors to upload, move, and delete files, and setting a password to protect your Public folder. To edit preferences simply click the Action button (gear icon) in the iDisk web application and select Preferences. You can then upload or move files to your Public folder at me.com, and your friends can access them by visiting http://public.me.com/[YourMemberName].