I was using just the regular backup on iTunes..
Big mistake, but lesson learned.
Were you using anything on your Mac or elsewhere for storing contact info and calendar events before you purchased an iPhone?
I suggest that you start syncing contact info with the Address Book and calendar events with iCal on your Mac. If the Address Book and iCal on your Mac are not being used and have never been used, enter one unique contact in the Address Book and one unique calendar event in iCal on your Mac before syncing contact info and calendar events. Make these up if needed, which can be deleted later. This will provide a merge prompt for this data, which you want to select.
Go to iTunes preferences. Under the Devices tab, is there more than one backup for your iPhone available?
If not, the backup for your iPhone was overwritten, and there is no way to recover the lost info.
You should have been syncing this data with the Address Book and iCal on your Mac, which doesn't require having a MobileMe account.