The top menu contains links to publically available resources. The bottom menu contains links to member-only resources. To access them you need to have an account (it's free).

If you register with an OpenID, your account is automatically created without a password. This way you can only login with your OpenID. Should you however want to create a password, that can be done on the Settings page once logged in. Please note however that once you create a password, you cannot remove it. Also, if you remove all OpenIDs attached to your account without creating a password, you will be unable to login. In this case, use the "Forgot your password?" feature.

Notes is an online notebook. Use it to save important notes, and access them later from any web browser.