As you know Google offers you plenty of things. Yes Google has a right way if you want to download or export your Google product data. It is called Google Takeout. Personally I love its name as its simple and meaningful. You can download your Gmail contacts, Google Buzz posts, Picasa Web photos, Profile data etc in couple clicks. Actually this is good as a backup too since you can import your data if something goes wrong with your Google products data. As an example imagine someone hacked your Picasa web photos and deleted all your pictures.
To download Google product data go to www.google.com/takeout and click on “Create Achieve” button.
It will create a zip file for you. Then you can simply download it.
Note : With Google Takeout you can especially download Google Buzz data as Google is going to retire Google Buzz in few weeks.