I signed up for a test account with MobileMe so that I could see what the programs look like and how it works. The experience I have had with it so far does not make me want to spend 99 dollars a year on the service as Google is pretty much providing the same services for free at the moment.
The programs are nice and the mail application works like a desktop program, which is nice. It does however not work incredibly on the Windows machine at work. It slow down Firefox a lot and sometimes freezes it for 30 seconds.
The calendar is not as good. On my computer, I subscribe to my Google Calendar so that I have all that information open all the time without having an extra tab open in my browser. Google Calendar syncs with my Outlook Calendar at work and from that I get a digital hard copy on my home computer, all three calendars have the same information. The only problem with this on the home machine is that I cannot update the calendar because it doesn't sync with Google Calendar, it just subscribes to it. The problem with MobileMe and this feature is that it won't sync calendars that you subscribe to. There is not even an option in the Calendar application to subscribe to a calendar, which makes it even more annoying.
Contacts works just like I thought it would and syncs really well to my iPod Touch. Again, it is a great looking program and works just like a desktop application.
I have no need for the Photo Gallery application because I think Flickr does a great job already, so I haven't played with it.
iDisk remains the same and works well.
The big feature that I am interested in trying out, but can't due to my laptop sleeping issues, is Back to My Mac. Once I get my laptop back in my possession I will try it out. I have been using screen sharing with my parents a little bit and assuming that Back to my Mac works in a similar fashion it should be a good feature. In fact it would be nice to use in conjunction with iDisk because if you had forgotten something you can just log into your computer at home, drop it into your iDisk and then download it on the machine you are on. Though with connection speeds over here, I don't think I will be using it for streaming music to my laptop.
UPDATE: Mobileme is now blocked at my office. Seriously getting ridiculous with the whole blocking thing.