Many of us use Outlook and Gmail at the same time for professional and personal work connect. Alternatively, some of us use IMAP or POP so that we can get Outlook like convenience on Gmail. But in both of these cases, managing similar contacts is a common problem. A decent solution to this problem is either way synchronisation of contacts between these two mail clients.
PPPIndia is one such Indian company that understood this problem pretty well and came up with excellent automatic contacts synchronization tool. This software is entirely free and you can download it from here. It works for all Gmail accounts as well as Google Apps account. On the Outlook side, it supports 2003, 2007 and 2010 versions.
With this freeware, you can either synchronize Gmail to Outlook contacts, which put all your Gmail contacts in Outlook [there could be additional Outlook contacts as well] or do an Outlook to Gmail sync, which moves all your outlook contacts to Gmail.
After you download this automatic sync tool, you will have to enter your Gmail credentials into the program. Then you will have to select the outlook folder or account with which you want to synchronize your contacts. Now choose any of the two options and select synchronize. The tool will now take contacts from both the clients and match them for similarity. Once the program starts running, you can minimize it in the system tray and it will automatically synchronise all the contacts. However, the empty ones (without any last name or with black email address field) will be left unaltered. You will have to manually deal with them. The program will keep you notified with pop-up balloon messages about errors or successes. The whole process may take a while (up to 10 minutes) depending on the size of your contact list.
Use this tool once in a while if you want an organized contact list between devices. Another advantage of this tool is that you can use all your Gmail contacts even offline or save them as a backup.
Note: Another less popular tool to two way Google Contacts and Outlook sync is Gcontactsynch. This is open source hence more trustworthy but doent not offer automatic synchronization facility.