I've just completed my Google Profile which you may view here.
A Google profile is simply how you present yourself on Google products to other Google users. It allows you to control how you appear on Google and tell others a bit more about who you are.
With a Google profile, you can easily share your web content on one central location. You can include, for example, links to your blog, online photos, and other profiles such as Facebook, LinkedIn, and more. You have control over what others see. Your profile won't display any private information unless you've explicitly added it.
You can also allow people to find you more easily by enabling your profile to be searched by your name. Simply set your existing profile to show your full name publicly.
If you've been writing reviews on Google Maps, creating articles on Google Knol, sharing Google Reader items, or adding books to your Google Book Search library, you may already have a profile. Click here to learn more about Google Profiles.