Google Accounts lists all accounts and services that you use on Google. Google Dashboard lists accounts where they store data. You may be surprised at how many you have. I have 24.
And while you’re at it, set up a Google Profile too ( if you haven’t already.) It’s a good way for people to find you. Tech blogger Robert Scoble says he got a White House invite from his Google Profile because he had his email address accessible. Here’s mine.