GcontactSynch is a .net framework based application which lets you synchronize contact details between your Gmail or Gmail Application accounts ( including the standard edition ). This way you can even synchronize contact between all the other email account as Contacts are centralized in Outlook.
You can choose how the update will take place i.e. Either you will need to over ride Outlook contact details or Google Contact Details. Since its not good idea to hit your Gmail account in mass i.e. if your address book is too big it can cause an issues, you can set synchronization interval and you can also check server logs.