From LivePIM Software:
GG Duplicates Cleaner lets you remove duplicate information in Google Contacts and Google Calendar quickly and smartly. GG Duplicates Cleaner provides a wizard user interface lets you check and remove duplicate information step by step. You may delete the duplicate records you selected or delete all the duplicate records with a simple click. GG Duplicates Cleaner also provides options let you customize your own duplicate checking rules which you may remove duplicates as you wish.
What's new in this version:
Version 126.96.36.1991 add a "go back" link on the finish page.