If you have an account with Google, AIM, Yahoo, Netlog or OpenID you can just click on the Google Login button found at the login page enter your credentials on Google and that's all, you'll be authenticated on our site and be able to use all functionality, including downloading.
Current added functionality available to GFC members is "invite friends", we are working to add more social features soon.
Please note that due this new login interface will create a new user nickname linked to Google Friend account, this is aimed to new users. Current registered users, specially current premium members must continue using their credentials as nowadays.
UPDATE: It is working with IE, Firefox, Chrome, and Safari.
Opera is not supported yet, and don't seems to be supported on a near future.