Sometimes when you synv your calendar events and contacts events on your iPhone or iPod Touch with MobileMe, the contact and events disappear on your device. Needless to say, this is a little scary. But don't worry, your data is still there on MobileMe, it's just not on your phone. Usually MobileMe lets you know on their websites when they are having known sync issues, and hopefully once they work things out, your events and contacts will be correctly updated.

But it's happened to me a couple of times where even after things are supposed to be fixed, my events and contacts don't update. The fix I found for this is temporarily turn off the sync, then turn it back on. This seems to reset things in such a way that the updates then happen.

To do this go to Settings -> Mail, Contacts and Calendars and then select your MobileMe account. Move the sliders to turn syncing OFF for Calendars and Contacts. Let it sit for a minute. Then move the sliders to turn the sync back on. Next time the sync happens (within 15 minutes), you should have your contacts and events back.