Gmail's undo send feature is a godsend for those of us constantly trying to recover from our mistakes, and now Google's added a similar feature for Contacts. Now, you can restore your address book to any state from the past 30 days.
Whether you've accidentally deleted a few contacts that you still need, or you accidentally lost everything while syncing to a new Android device, you can now restore your contacts list to a saved state from the past 30 days. All you need to do is go to Gmail's Contacts section, hit "More Actions", and go to Restore Contacts. It will give you a list of times from which you can restore your address book. And, if you make a mistake and restore it to a point too far back, you can always move it back forward. It's a great little feature if you're using Google Contacts as your central, unified address book, and sure to save you many a headache in the future. Hit the link to read more.
Restore Your Contacts [Official Gmail Blog]