One of the things I looked at when I bought my first Mac, was Mobile Me . This is a service from Apple that helps you out. Are you the type of person with multiple computers? Or what about an iPhone/iPod Touch? If so then Mobile Me is for you. The feature I use the most is the contact and Calendar synchronized. So if I add a calendar event on my iPod Touch and go to my iMac, the event is there. If I edit it there and go to my iPod it is updated there. The sync is pretty instant. Only requirement is everything needs to be online. So both computers need to be online. If they are not they will not get the update till it does go online. This service is not limited to just Macs.
Now Mobile Me does more than just contacts and calendar events. It also works with emails, bookmarks, and even setups up a remote storage center. You can use this to get files while away from home. The last feature that you get with this is free web space with picture gallery support. With the gallery support if you own a Mac will allow you to upload your albums right from iPhoto . Now that is convenience.
As far as price it is $99.99 USD for the year. This needs to be paid up front and needs to be renewed every year. Now if you look and your typical hosting accounts it is almost $10.00 USD a month. So it is not too expensive but well worth it. It was great when I reformatted my Mac. Once the OS was installed Mobile Me downloaded to my computer, e-mail, contacts, calendar, and bookmarks. I could even go into iPhoto and pull my albums down from the cloud. Overall it is worth getting and you should not go with out it.